2012 Flashcards

Question

Calcium reabsorption induced by parathyroid hormone and Vitamin D occurs primarily in the: 1. proximal convoluted tubule 2. collecting duct 3. thick ascending loop of Henle 4. distal tubule 5. proximal straight tubule.

Answer 1

4 The site of action of both parathyroid hormone (PTH) and Vitamin D is on the distal tubule. Calcium resorption occurs in this region of the kidney architecture under hormonal influence. Calcium is reabsorbed in the proximal convoluted tubule as well, but the difference is that it is not under the influence of PTH. The collecting ducts and tubules as well as the loop of Henle are not responsible for calcium resorption and homeostasis.

Answer 2

2 Radionuclide bone scans may reveal delayed concentration of tracer in the kidney due to a generous collecting system or due to true obstruction. This finding should be confirmed by a functional study such as an contrast CT scan or nuclear renogram, which should help determine whether or not this represents a functionally significant obstruction. More invasive procedures such as cystoscopy and retrograde pyelogram, or an antegrade pyelogram are not indicated at this point. Serial creatinine measurements will help follow overall renal function but will not determine functional obstruction. Renal ultrasound is an anatomic study and may show hydronephrosis but will not determine if it is functional.

Answer 3

4 The 2010 AJCC staging for penile cancer made several significant changes. This patient has a pT1 tumor because of his subepithelial connective tissue involvement. Those patients with low grade tumors and without lymphovascular invasion are pT1a. This patient, however, has lymphovascular invasion and as a result is a pT1b. Patients with lymphovascular invasion are in fact at higher risk for metastatic disease. For the first time, nodal staging is divided into both clinical and pathologic staging schemes. With a palpable, fixed nodal mass, regardless of the size or unilateral/bilateral involvement, the clinical lymph node status is cN3.

Answer 4

2 This patient has urgency incontinence secondary to detrusor overactivity, as indicated by the random nature of the incontinence. Even though idiopathic detrusor overactivity implies the presence of involuntary bladder contractions in the absence of neurologic disease, a CMG will fail to demonstrate involuntary bladder contractions in approximately 50% of patients with clinical urge incontinence. Detrusor overactivity with impaired contractility and overflow incontinence is not the cause in this case since the PVR is low. The primary cause of the incontinence is not stress (increase in abdominal pressure) related, particularly not intrinsic sphincter deficiency, since urinary leakage did not occur during Valsalva maneuvers. The characteristics of the incontinence are not consistent with a vesicovaginal fistula since the urinary leakage is not continuous.

Answer 5

2 During normal pregnancy there is a physiological state of absorptive hypercalciuria. Placental production of 1,25-dihydroxycholecalciferol increases intestinal calcium absorption and secondarily suppresses parathyroid hormone. Urinary citrate and glycosaminoglycan excretion (inhibitors of stone formation) are increased. Therefore, overall stone rate during pregnancy is unchanged.

Answer 6

2 The ECOG Performance Status, also called the WHO or Zubrod score runs from 0 to 5, with 0 denoting perfect health and 5 death. 0 - Fully active, without restriction. 1 - Completely ambulatory, but restricted in physically strenuous activity. Able to carry out work of a light or sedentary nature such as light housework or office work. 2 - Ambulatory and capable of all self care but unable to carry out any work activities. Out of bed \> 50% of waking hours. 3 - Capable of only limited self-care and confined to a bed or chair \> 50% of waking hours. 4 - Completely disabled. Cannot carry on any self-care. Totally confined to bed or chair. 5 - Death

Answer 7

5 Factors that may increase leakage in patients with an orthotopic neobladder include: shortened functional urethral length, non-nerve sparing, decreased membranous urethral sensation, and increased time after diversion (as patients age.) Formulation of a funnel-shaped reservoir in fact increases kinking and increases the likelihood of failure of spontaneous voiding. Nerve-sparing may in fact aid in the functionality of the neobladder although exact mechanism is unknown. No data exists for a placement of urethral sling being helpful in maintaining continence and may promote hypercontinence.

Answer 8

1 Pyridoxine reduces oxalate production in up to 50% of patients with mild hyperoxaluria. Pyridoxine, a component of Vitamin B6, is a co-factor for alanine:glyoxylate aminotransferase (AGT), which converts glyoxylate to glycine. In doing so, less glyoxylate is available as a substrate for LDH which leads to a decrease in endogenous oxalate production. The other agents will have no impact on urinary oxalate.

Answer 9

2 The use of both vitamin supplements and alpha interferon has become common in conjunction with BCG therapy. Recently a randomized prospective trial of 670 patients was completed to address these issues. BCG alone with RDA vitamins was associated with an equal disease free outcome when compared to combinations of interferon or mega dose vitamin supplements. Megadose vitamins showed no increased benefits when compared with RDA vitamins. All patients were treated with induction and maintenance BCG. Patients receiving interferon experienced greater side effects, particularly fever and constitutional symptoms. There is no compelling evidence to suggest that patient should discontinue RDA vitamins/

Answer 10

4 This patient suffers from bladder outlet obstruction secondary to a large cystocele as indicated by a high voiding pressure and low flow rate. The obstruction secondarily causes detrusor instability and subsequent urgency incontinence. Despite reducing the cystocele, no stress incontinence can be elicited indicating good support of the urethrovesical junction. The best treatment is to repair the cystocele with a technique such as anterior colporrhaphy. The absence of stress urinary incontinence precludes the need for a sling and if performed alone is likely to exacerbate the obstruction. Treatment with antimuscarinic medication in a patient with obstruction is likely to increase the PVR. Although alpha-blockers may be used off-label for primary bladder neck obstruction in women, the best treatment in this patient with a large cystocele is to correct the underlying abnormality.

Answer 11

4 The efficacy of estrogen for the prevention of UTI in post-menopausal women has been demonstrated in several studies. There appears to be a higher effectiveness rate in topically applied estrogen in the vagina with an improvement in lactobacillus concentrations, decreased vaginal pH and a decrease in UTI episodes from 5.9 to 0.5 episodes per year. Antimicrobial prophylaxis may be used at low dose if topical estrogen fails. Lactobacillus probiotics, while effective in an investigational setting, have not been subject to the scrutiny of controlled trials.

Answer 12

4 A chemotherapeutic intervention proven to prolong survival in the setting of metastatic castrate resistant prostate cancer resistant to docetaxel is cabazitaxel. This regimen was FDA approved for this indication in 2010 and demonstrated a 30% reduction in the chance of dying of prostate cancer in a prospective phase III randomized trial. Mitoxantrone served as the control arm of the trial and has not been associated with a survival advantage in prostate cancer. Sipuleucel-T has been proven to extend survival in asymptomatic metastatic castrate resistant patients. Ketoconazole has not been proven to demonstrate a survival advantage in this setting and switching to weekly docetaxel has also not been associated with a survival advantage. Abiraterone, an androgen biosynthesis inhibitor has reported a survival difference as well in a phase III trial compared against placebo.

Answer 13

3 Revascularization to preserve renal function in patients with atherosclerotic renal artery stenosis will most likely benefit those who have not yet sustained permanent global impairment of renal function. Complete occlusion of the renal artery does not necessarily preclude intervention, since renal viability may be maintained through the presence of collateral arterial supply. The Cleveland Clinic group has found that 89% of such patients with initial serum creatinine \< 3.0 mg/dl could be expected to have stable or improved renal function after revascularization. However, renal biopsy to evaluate the severity of renal parenchymal involvement as a guide to revascularization was found to be helpful only if the initial serum creatinine exceeded 4.0 mg/dl. In addition to the absolute level of renal function, the rate of decline of renal function is an important determinant of outcome after intervention. Duration of HTN does not predict recoverability in this setting.

Answer 14

2 Prior to harvesting a Buccal graft or other graft for repair of an anterior urethral stricture, ultrasound can easily identify the area of stricture as well as the area of scarred urethra which must be resected to adequately restore urethral continuity using an onlay graft. Sonourethrography has been shown to be a useful adjunct to standard radiographic imaging of bulbar urethral strictures. Although it can aid in the visualization of the corpus spongiosum including vascular structures, calcifications, and periurethral fibrosis, incorporation of this information into surgical decision making algorithms has not followed. The primary benefit of ultrasound imaging is the lack of distortion created by the oblique position during retrograde urethrogram (RUG). Thus the sonogram will more accurately measure the length of the stricture. In bulbar urethral strictures of intermediate length, RUG will underestimate the true length of the stricture by up to 13 mm. VCUG can delineate the urethra proximal to the stricture unless the patient is unable to void, in which case sonography may allow visualization of the posterior urethra by vigorous suprapubic pressure under anesthesia. Urethroscopy will not demonstrate underlying spongiofibrosis, while VCUG and retrograde urethrography are subject to distortion and measurement error. CT urethrograms have only been used to identify acute injuries of the urethra.

Answer 15

1 Post-transplant lymphoproliferative disorders are most commonly non-Hodgkin lymphomas and are often associated with Epstein-Barr virus infection. The reported incidence ranges from 0.8% to 15%, and varies with the type of immunosuppression utilized. These tumors may respond to drastic reduction or withdrawal of immunosuppression. Irradiation is not generally effective and may exaggerate the degree of immune compromise. Treatment with anti-viral medications such as ganciclovir may be beneficial following reduction in immunosuppression. Rituximab (anti CD-20) and chemotherapy are second line therapies for this type of tumor. Nephrectomy may be necessary, but is not the initial treatment.

Answer 16

4 This patient has a high detrusor LPP that puts his upper urinary tract at risk. Since he is a quadriplegic and is managed with a condom catheter, the next best step is an external sphincterotomy that can be done surgically or pharmacologically with injection of botulinum. Observation and a male sling do nothing to reduce the effects of his bladder on the upper urinary tract. CIC is usually not feasible for quadriplegics and would not be helpful in this situation since the functional bladder capacity is only 150 ml. Antimuscarinic medication alone would also not be helpful since it would not decrease the detrusor leak point pressure.

Answer 17

4 Ammonium acid urate stones are rare. They are found in patients with chronic diarrhea and a history of laxative abuse. These patients have low urinary sodium excretion. Their urinary citrate levels are usually low secondary to bicarbonate loss from the gastrointestinal tract. Urine pH is usually above 6.3; when urine pH is below 5.5 uric acid will likely precipitate. Ammonium acid urate stones are also found in patients with ileal resection or with large portions of their colon removed. Chronic diarrhea and UTIs are additional risk factors. Ammonium acid urate stones are relatively radiolucent and may be mistaken for uric acid stones. Ammonium acid urate stones do not dissolve with alkalinization. Calcium phosphate stones typically form in the setting of hypercalciuria and/or hypocitraturia and are not associated with laxative abuse.

Answer 18

1 After a successful dismembered pyeloplasty, it is not uncommon for a delayed opening of the anastomosis when using nephrostomy drainage. As long as the patient is doing well clinically, the best management during the early post-operative period is patience and repeat assessment to allow the anastomotic edema to subside further. Repeat nephrostogram in two weeks is the appropriate next step. Some have advocated a simple clamping trial of the nephrostomy tube and check the residual amount afterward. MR urography and a Whitaker study are unwarranted during the early post-operative period, as are the retrograde pyelography/stent placement and conversion of the nephrostomy tube to a nephroureteral stent. Stent placement could also damage the anastomosis.

Answer 19

4 Abnormal bleeding times in patients with renal failure are due to poor platelet aggregation. The coagulopathy may be reversed transiently by desmopressin, cryoprecipitate, conjugated estrogens, blood transfusions, erythropoietin, or dialysis. However, Vitamin K has no activity in the setting of reversing platelet dysfunction in ESRD. Similarly, fresh frozen plasma will affect the coagulation cascade but that shouldn't be abnormal in ESRD patients. Platelet transfusion is not helpful in the setting of normal platelet count as aggregation is not improved with more platelets.

Answer 20

2 Urethral meatal bacteria are the most frequent source of catheter-associated urinary tract infection. Unfortunately, topical urethral meatal antimicrobial agents do not prevent urinary tract infections and frequently cause overgrowth of resistant bacteria. Improper catheterization techniques, breaks in the system, and contamination of the drainage bag are less frequent but preventable causes of catheter-associated infection. Antimicrobials allow growth of resistant bacteria that are more difficult to treat but not more likely to cause infection.

Answer 21

3 This boy likely has a neuroblastoma. 50% of these tumors present in children under the age of two. These tumors are usually large, hard, and fixed. Children will often have numerous other paraneoplastic syndromes. Catecholamine release from the neuroblastoma can result in symptoms that can mimic pheochromocytoma including paroxysmal HTN, palpitations, sweating, and headaches. However, pheochromocytomas tend not to be large masses like this and present in older children. Wilms' tumor usually presents in children a few years older and the masses are more likely to be smooth and less fixed. HTN can also be seen but is less common. Congenital mesoblastic nephroma is possible but is usually seen in infants a few months of age and is the most common renal tumor in children less than six months of age. Autosomal recessive polycystic kidney disease can present at any age with a wide spectrum of symptoms. It involves both kidneys and you should be able to palpate bilateral masses. When it presents early in life, it is usually severe and associated with significant renal insufficiency.

Answer 22

5 Cirsoid arteriovenous fistulae are generally congenital in nature. This must not be confused with the much more common arteriovenous fistulae that results from iatrogenic kidney needle biopsies. Treatment for the congenital cirsoid lesion is indicated in patients with HTN, cardiomegaly, heart failure, severe hematuria, or angiographic evidence of expansion of the lesion. ACE inhibitors and beta-blockers are not effective in the treatment of this anatomical defect. Cirsoid fistulas are not like a simple arteriovenous connection where one can just ligate a vessel and the lesion is resolved. Due to the complexity of the lesion, angio-embolization is generally considered difficult if not impossible and the patient is at risk for complications, particularly coil migration. Nephrectomy is the treatment of choice. The importance of this concept is to recognize that cirsoid arteriovenous fistula is a different entity than an iatrogenic arteriovenous fistula from biopsies and thus, the treatment is different.

Answer 23

3 Among the conditions this man has, only the ectopic production of parathyroid hormone related peptide would explain his stone formation. E. coli is not a urease producing organism and thus should not cause a stone. Given a history of peptic ulcer disease, a stone can form due to the development of milk-alkali syndrome, however, this is not one of the listed choices. The presence of hypercalcemia rules out secondary hyperparathyroidism. While absorptive hypercalciuria likely is playing a role in this patient, it is more likely due to the effect of ectopic production of parathyroid hormone related peptide due to the hypercalcemia present (homology to PTH in the first 13 amino acids). This ectopic production is most commonly seen with squamous cell carcinoma of the head, neck or lung (as in this case).

Answer 24

2 Recurrent UTI in school age girls are significantly related to the following factors; a family history of recurrent UTI, a history of infrequent voiding, diurnal incontinence, poor fluid intake, and constipation. Recurrent UTI rates have not been found to be significantly associated with isolated nocturnal enuresis, race, the presence of VUR, or whether or not the initial infection was febrile in nature.

Answer 25

1 The patient most likely has an anastomotic stricture and stress incontinence. The 10 Fr catheter is occluding the bladder neck, preventing demonstration of stress incontinence. A repeat urodynamic study with a suprapubic catheter is not necessary since the bladder capacity is known to be normal and there is no evidence of overactivity, and may be overly aggressive. Cystoscopy and retrograde urethrogram would demonstrate the stricture, however these studies would not demonstrate stress incontinence. The simplest study to determine the etiology of the incontinence is removing the urodynamic catheter with the bladder full and asking the patient to Valsalva in order to evaluate sphincteric function.

Answer 26

4 In boys with proximal hypospadias, the prostatic utricle is often enlarged due to a lack of androgen action. In the female, this would represent the distal 1/3 of the vagina. The ultrasound demonstrates a midline cystic structure behind the bladder which is consistent with a prostatic utricle. While an ectopic ureter, bladder diverticulum, or mesonephric duct cyst could have a similar appearance, they are usually lateral in location. In addition, the history of proximal hypospadias would make a utricle most likely. A Cowper's duct cyst should be confined to the bulbous and prostatic urethra.

Answer 27

4 The blood supply for both the right and left adrenal glands is the same. The three sources for each adrenal gland are derived superiorly from branches of the inferior phrenic artery, in the middle directly from the aorta, and inferiorly from the ipsilateral renal artery.

Answer 28

1 This patient has a high probability of having renal artery stenosis. By removing one kidney the situation becomes analogous to the one-kidney, one clip model. In this situation, HTN is largely maintained by volume and sodium excess. In the face of normal circulating angiotensin II (AII) levels, ACE inhibitors or AII antagonists do not result in marked decrease of blood pressure. Calcium channel and alpha-blockers also are not very effective until the volume overload has been treated. Since the etiology of HTN is intravascular volume expansion, the best choice is a diuretic.

Answer 29

5 Most patients with blunt trauma and microscopic hematuria do not need imaging. The SIU Consensus Statement on Renal Injuries recommends imaging to detect blunt trauma only in selected patients. Adults with gross hematuria or microhematuria and hypotension have a major (e.g. Grades 3,4,5) injury rate of approximately 12.5% and thus warrant further imaging. These recommendations were derived from a number of studies including the seminal article by McAninch and associates in 1989. A review of 2,254 patients with suspected renal trauma seen from 1977 to 1992 was performed by McAninch and colleagues. Of the 1,588 blunt trauma patients with microscopic hematuria and no shock, three had significant injury but these cases were discovered during imaging or exploratory laparotomy for associated injury. Follow-up of 515 of 1,004 patients (51%) who did not undergo initial imaging revealed no significant complications. Adults with blunt renal trauma, microscopic hematuria and no shock (systolic pressure \< 90 mm/Hg) or major associated intra-abdominal injuries can safely be spared radiographic imaging.

Answer 30

4 This patient most likely has bladder perforation related to resection at the base of one of these superficial tumors. The bladder dome is often quite thin and is at high risk for perforation during resection. Also, obturator nerve stimulation can cause muscular spasm during resection of a laterally located tumor and this sudden motion may lead to perforation with the resecting loop. The monopolar current requires glycine or another non-electrolyte containing solution to be used in order to avoid dispersion of the current. Extravasation of the irrigation solution is the likely cause of the suprapubic distension. Glycine is quickly metabolized in the liver after absorption and is unlikely to be detected in the serum. However, the remaining extravesical fluid is free water and will cause acute dilutional hyponatremia as it is absorbed. Ammonia should not be elevated in this circumstance and serum BUN only goes up over a longer period of time if there is extravasation of urine with secondary resorption from exposed tissues. It is unlikely that there has been vessel injury from these superficial resections that is severe enough to cause anemia and suprapubic distension acutely.

Answer 31

1 Approximately 10% to 20% of pheochromocytomas are malignant and malignancy is more common in tumors larger than 5 cm and in extra-adrenal tumors. Observation is the most appropriate therapy in a fully resected asymptomatic patient. Mitotane has proven palliative benefit in cases of metastatic adrenal cortical carcinoma. Metyrapone and aminogluthamide can be use to ameliorate hormonal production in metastatic adrenal cortical carcinoma. Somatostatin or octreotide has limited use in the palliative treatment of secreting metastatic pheomochromocytoma causing HTN. Radiolabeled MIBG therapy can be useful in symptomatic patients with a positive MIBG scan for metastases. Combination chemotherapy has been used in the treatment of metastatic pheochromocytoma with some limited success. The most commonly used regimen is cyclophosphamide, vincristine, and dacarbazine.

Answer 32

5 Asymptomatic bacteriuria is particularly common in elderly women. There is evidence in adults that while 80% of patients with asymptomatic bacteriuria can be cured with a seven day course of oral antimicrobial therapy, long term cure rates are no better than placebo therapy because of reinfections in treated patients and spontaneous cures in untreated subjects. Moreover, treatment of asymptomatic infections, which are often associated with self agglutinating E. coli that have lost their O polysaccharide surface antigens, is frequently followed by a new E. coli infection with intact O surface antigens that are apparently responsible for acute symptoms. For this reason a sound argument can be made against treating an asymptomatic infection just to achieve low growth in the urine for a short period of time.

Answer 33

4 Bladder stone formation is a frequently encountered complication after enterocystoplasty. The most effective preventive measure appears to be regular bladder irrigation. There is no definitive data to support other measures such as frequent CIC, potassium citrate, or antibiotic suppression to decrease the incidence of bladder calculi. Conversion to ileocystoplasty will not significantly reduce the risk of bladder calculi.

Answer 34

3 Spinal shock after spinal cord injury is the result of absent somatic reflex activity and suppression of somatic and autonomic activity below the level of the injury. It typically lasts six to twelve weeks but can last up to two years. At four weeks after injury, spinal shock continues and is manifested by bladder areflexia, a functional smooth sphincter and an absent guarding reflex (the ability of the striated sphincter to contract during bladder filling). After spinal shock, a T8 SCI patient is likely to have detrusor overactivity, smooth sphincter synergia (because T8 is below sympathetic outflow) and absent guarding reflex.

Answer 35

5 Cystinuria should be managed initially with hydration and, perhaps, alkali therapy. The solubility of cystine does not significantly increase until the urinary pH reaches 7.5. At this pH, calcium phosphate precipitation may occur. Specific therapy would include use of either D-penicillamine or alpha-mercaptopropionylglycine (Thiola). D-penicillamine is less well-tolerated and approximately 50% of patients stop this therapy due to side effects. Tham-E is an alkalinizing agent used for irrigation. Acetohydroxamic acid is a urease inhibitor used for the management of infection stones. Captopril may be effective in reducing urinary cystine excretion in patients who have not responded to therapy with alpha-mercaptopropionylglycine and D-penicillamine or who are intolerant of these agents.

Answer 36

1 This is a typical scenario of a pediatric postinfectious glomerulonephritis. It is often preceded by either pharyngeal or skin streptococcal infection between 7 to 21 days. The most common presentation is painless gross hematuria, with accompanying mild proteinuria, edema and HTN. The C3 is low in 85-95%, and the streptozyme test is positive when preceding infection was a streptococcal infection. The prognosis is excellent, and the treatment is supportive. Gross hematuria resolves in several days, and proteinuria decreases during the first several weeks. In this clinical scenario where the etiology of the gross hematuria is evident, further diagnostic tests are not indicated. Renal biopsy should be considered in the presence of persistent hematuria and proteinuria.

Answer 37

1 The image demonstrates an upper calyceal diverticulum. SWL is not recommended for the management of calyceal diverticulum with a narrow diverticular neck, as shown here, as fragments are unlikely to clear. PCNL and laparoscopy are appropriate alternatives for management of a calyceal diverticulum. However, before the choice of procedure can be made, it is important to determine whether the diverticulum is in an anterior vs. posterior location, as well as the relationship of the pleura and adjacent organs. PCNL would be utilized for a posterior diverticulum, while laparoscopy would be utilized for an anterior diverticulum. A CT scan without contrast will provide information for each of these variables. The CT scan will also determine the amount of parenchyma overlying the diverticulum. I.V. contrast would not be necessary as the retrograde pyelogram delineates the calculi within the diverticulum.

Answer 38

3 Natural cycle refers to allowing the woman to ovulate on her own without pharmaceutical induced stimulation of the development of multiple follicles through ovulation induction. In men with male factor infertility due to abnormal semen parameters, natural cycle intracervical or intrauterine insemination (IUI) is no better than timed vaginal intercourse. Those techniques are only useful in infertility caused by mechanical problems such as hypospadias, retrograde ejaculation, or impotence. Natural cycle IUI is useful in pure cervical factor infertility. Pregnancy rates with IUI are increased in couples with abnormal semen parameters if the woman undergoes ovulation induction. Clomiphene citrate and gonadotropins are commonly used medications for ovulation induction. Women with tubal abnormalities are best treated with in vitro fertilization since inseminated sperm still need to ascend through the fallopian tubes. The higher the total motile sperm count the better the pregnancy rate, therefore those with a sperm count \> 10 million will fare better than those with \< 10 million.

Answer 39

1 Voiding dysfunction and incontinence are common in boys with history of PUV. Over 80% will struggle with incontinence at age five. Nocturnal bladder drainage is usually indicated in the presence of high urinary output which can occur in boys with a history of PUV secondary to a concentrating defect. In such patients, significant hydroureteronephrosis is expected, which this patient does not have. Since he is not retaining urine after voiding, urodynamic test will likely demonstrate a pattern of bladder overactivity. However, it is appropriate to try conservative measures such as timed voiding prior to proceeding with more invasive testing such as urodynamics. Oxybutynin must be used with caution since a possible underlying myogenic dysfunction could lead to outright urinary retention. Desmopressin will not affect bladder dysfunction, which is the primary etiology of incontinence in boys with PUV.

Answer 40

4 New onset symptoms in a geriatric patient with previously diagnosed asymptomatic bacteruria warrant therapy. Generally, seven days of therapy is suggested. Single dose therapy is inadequate in this setting. There is no indication for catheterization as the patient is symptomatic and has a positive urine culture. Although this patient may need an evaluation for recurrent UTI's at some point, this evaluation can be delayed until she is adequately treated for her current symptomatic infection. Treating with estrogen alone in a settting of a symptomatic infection is insufficient. Initiating estrogen therapy in patients with recurrent symptomatic UTIs and atrophic vaginitis would be appropriate.

Answer 41

3 The location and nature of pain and/or colic can often times determine the location of ureteral calculi. Classically, patients who report flank discomfort with radiation anteriorly most often have stones located in the proximal or mid-ureter. More commonly, patients with stones in the distal ureter will report irritative voiding symptoms or pain radiating to the penis, scrotum, or labia. With a normal urinary stream and no associated bladder symptoms, it is unlikely that this patient has a stone either in the urethra or bladder, respectively.

Answer 42

3 Spina bifida occulta is often identified on spine films. In a child with a normal physical examination the chance of a spinal cord abnormality is very small. These children should be treated the same as other children with urgency and daytime wetting. The initial management is timed voiding and maintenance of a voiding diary. Since it is very likely that this VUR will resolve with behavioral modification surgical management including endoscopic treatment is not indicated. Urodynamics would be reserved for those children that are refractory to medical management. MRI scan of the spine is not indicated.

Answer 43

2 A frequent complication of bladder outlet surgery for the treatment of obstruction is retrograde ejaculation. While this can be overcome with bladder harvested sperm most men who desire to maintain their fertility want normal antegrade ejaculation. The incidence of retrograde ejaculation is very high after TURP (up to 95%). TUIP has a much lower incidence of retrograde ejaculation (0% to 37%) and in many series is as effective as TURP. With a unilateral incision the incidence of retrograde ejaculation is less than 5%, and with two incisions, it is 15%. Laser vaporization has an associated risk of retrograde ejaculation that may be as high as TURP. While CIC would likely preserve antegrade ejaculation it is less desirable in a healthy young man.

Answer 44

3 Scattering of the primary beam from the patient is the primary source of radiation exposure to the operator during endourologic procedures. For this reason, maximizing the distance between the operator and the patient during fluoroscopy is a very effective method of reducing exposure. This explains why the fluoroscopy source is best placed under the patient to minimize radiation scatter to the operator.

Answer 45

5 To date, the etiology of primary nocturnal enuresis is poorly understood. Research has shown that many children will have a reduced functional bladder capacity and an element of overactive bladder contractions while sleeping. Most children will also have an element of elevated arousal threshold while sleeping. Many single and combination treatment modalities have been used including the urinary alarm, anticholinergics, DDAVP, and imipramine. However, the modality that has the highest success and the lowest relapse rate is the nocturnal enuretic alarm. The correct use of the alarm is commonly misunderstood. It is best used in conjunction with the parents' involvement in which they confirm that the child awakens when the alarm goes off since the child will often sleep through the alarm. The child then gets up and voids to completion. The alarm therapy may take up to three to four months to be successful. Parents and children need to be educated on its correct use and the labor intensive nature of this therapy. When used correctly, success rates have been reported to be 70-80% with low rates of relapse. All forms of pharmacotherapy have lower rates of success and much higher rates or relapse. Behavior modification using techniques such as timed voiding or retention training are not effective tools to address nocturnal enuresis.

Answer 46

1 This patient has detrusor external sphincter dyssynergia (DESD)based on the urodynamic evaluation. By definition, this implies the presence of a lesion between the pons and the lower spinal cord. Multiple sclerosis needs to be strongly considered given this patient's demographic information and urodynamic findings. Approximately 5-10% of patients with MS present initially with urologic complaints. Cystoscopy is not indicated, and bladder cancer is not likely in the age demographic and with a negative UA. Antimuscarinic therapy may ultimately be helpful, though the residual would need to be monitored closely in the presence of DESD. Patients should be evaluated for possible neurological process due specifically to the finding of DESD. Onabotulinum toxin injections should not be utilized until a definitive diagnosis has been made.

Answer 47

4 Scrotal reconstruction can be performed in many ways depending on the characteristics of the patient, mechanism of injury, and degree of skin loss. Limited skin loss can be managed with mobilization of remaining scrotal skin and direct closure as the scrotal skin is very pliable and will expand to cover relatively large defects. In this case a 90% loss makes this option impossible. More extensive skin loss can be managed with skin grafts, local flaps or tissue expanders. Rotational flaps provide a sensate and hair bearing scrotum but require more extensive dissection and have been generally supplanted by skin grafting. Full thickness skin grafts are reserved for selected cases where small surface areas are required and contraction is especially problematic, but not useful in this case due to 90% scrotal loss. Thigh pouches are acceptable but generally temporizing measures except in the most debilitated patients. Reconstruction is most easily accomplished with the use of split-thickness skin grafts which can cover large areas of skin loss and provide for complete scrotal reconstruction. Advantages of split thickness skin grafts include their high success rate and the fact that, when healed, they mimic the rugate appearance of the normal scrotal skin. Disadvantages include lack of hair and the fact that they may retract. Retraction can be minimized by avoiding expansion of the graft (i.e. 2:1 or 3:1 meshing). Skin grafts should never be placed on an acute injury due to bacterial contamination that will usually result in graft loss. Delayed grafting five to seven days post-injury in the presence of a clean graft bed will result in increased graft take.

Answer 48

4 The kidneys in children, as compared to those in adults are believed to be more susceptible to trauma for numerous reasons including a more pliable thoracic cage, weaker abdominal musculature, less perirenal fat, and lower position in the abdomen. Although there has been past controversy regarding the indications for imaging in children with blunt renal trauma, most studies now suggest that children should be radiographically evaluated in a similar fashion to adults. Thus, they should be imaged when one of the following four criteria are present: 1. A significant deceleration or high-velocity injury such as a high speed MVC, or fall from more than 15 feet, or significant blow to the abdomen, 2. Significant trauma that has resulted in fractures of the surrounding rib cage or spine, 3. Gross hematuria, or 4. Microscopic hematuria (\< 50 RBC/hpf) associated with shock (systolic blood pressure less than 90 mm Hg). CT scans are the best form of imaging. In this child, the degree of microscopic hematuria and the absence of shock does not fulfill the criteria for imaging. However, the mechanism of injury where airbag deployment was noted suggests a significant deceleration injury which mandates the need for imaging; thus a CT scan should be performed. The mechanism of injury is probably the most important factor in helping to determine whether imaging is necessary in borderline cases.

Answer 49

3 The motor and sensory responses noted are consistent with incorrect placement of the lead into the S2 foramen. The lead should be removed, replaced one foramen lower (S3), and re-tested. Placing more deep or shallow will not result in appropriate stimulation. Correct placement of the lead into the S3 foramen will result in a Bellows reflex, a contraction of the perineal area, and plantar flexion of the ipsilateral great toe.

Answer 50

4 In patients with urinary obstruction and impaired renal function, postobstructive diuresis is not unusual. Typically, urinary catheter drainage produces improvement in the blood levels of creatinine, BUN, and electrolytes to normal levels. If significant improvement does not occur, consideration must be given to inadequate drainage of the upper urinary tract because the bladder is poorly drained (poorly functioning catheter) or because of supravesical obstruction. The latter should be evaluated using renal ultrasound which is less invasive than retrograde pyelography. Since creatinine and BUN have not improved, continued observation is inappropriate until upper tract obstruction is ruled out. No data to suggest the need for immediate dialysis in this patient is provided. There is no evidence the patient is dehydrated, therefore increased fluid replacement is not indicated.

Answer 51

2 Children with hemihypertrophy are at risk for the development of Wilms' tumor due to alterations in the WTR1 and WTR2 genes. The best screening method to allow early detection of a renal mass, without untoward exposure to radiation or excessive cost, is ultrasound every three months through early childhood. Twice-yearly UA and urinary metanephrine are not indicated in this patient, because they are not predisposed to pheochromocytomas.

Answer 52

5 Autoinflation occurs when the inflatable penile prosthesis partially inflates with physical activity. It can be minimized by placing the reservoir in the prevesical (retropubic) space performing the back pressure test with reservoirs that do not have a lockout valve or by using a reservoir with a lock-out valve, is now available as an option. The cylinders should also be kept deflated during healing after surgery and when the prosthesis is not being used. Initial experience with this device suggests that it reduces the incidence of this complication.

Answer 53

1 The delayed appearance of sperm in the ejaculate of men undergoing vasoepididymostomy (VE) is common. The mean delay in one reported series was six months (range, 3 to 15 months). The ultimate mean sperm count and motility were found to be similar to subjects with sperm present in the initial semen analysis in this study. Therefore, observation would be the best approach in this situation. The epididymal fluid would have been examined for sperm at the time of VE and the procedure only performed if sperm were identified. Determination of the FSH would not be useful since FSH should be normal in patients with obstructive azoospermia. Clomiphene citrate will raise FSH, LH, and testosterone but not correct the obstruction. TRUS is indicated for ejaculatory duct, not epididymal obstruction. Testicular sperm retrieval is not indicated this early after surgery.

Answer 54

3 The clinical scenario of dribbling despite normal voiding creates suspicion of an ectopic ureter. Often the ectopic upper pole moiety of the duplex kidney is very small and not easily identified on ultrasound. In these cases an MRI scan or MR urogram are the best imaging tests to localize the difficult to identify small, dysplastic upper poles and their ureters. MR urogram is not always required since the T2-weighted images of a standard MRI are particularly suited for finding and defining fluid-filled structures like an ectopic ureter. Sagittal imaging may demonstrate the exact termination of the ectopic ureter. DMSA scan is most useful in the identification of small ectopic kidneys but is unlikely to be useful when the renal US is normal. If the moiety is small, a MAG-3 renal scan and IVP will appear normal because the upper pole has no function and the lower pole will not be deviated. VCUG will sometimes show VUR into an ectopic ureter depending on the location of the orifice. A retrograde pyelogram can identify the ectopic orifice but the orifice is often difficult to identify cystoscopically and is not as sensitive as an MRI scan.

Answer 55

2 Urodynamic stress urinary incontinence is defined as the presence of urinary leakage during a rise in intraabdominal pressure in the absence of a detrusor contraction. The presence of leakage with cough and or sneeze, defines the symptom of SUI. Leakage in the absence of a rise in intraabdominal pressure with a rise in detrusor pressure is the detrusor leak point pressure, most commonly encountered in neurogenic patients. This represents the relationship between bladder storage and outlet resistance.

Answer 56

1 Lymphoma accounts for about 5% of all testicular tumors. It is the most common of all testis tumors over the age of 50. The median age of occurrence is approximately 60 years. Lymphoma is the most common secondary neoplasm of the testis. Microscopically, all varieties of reticuloendothelial neoplasms, including Hodgkin's disease, have been described in the testis. The vast majority, however, are diffuse; of these, most are histiocytic. Of germ cell tumors in men over 50, seminoma is most common. However, in the presence of multiple testicular lesions in a 64-year-old man, lymphoma is the most likely diagnosis.

Answer 57

1 While this child may be male, consideration of the 46XX disorder of sex development secondary to CAH must be entertained. Laboratory evaluations to assess enzymatic adrenal function is the primary concern. FISH evaluation for the presence of a Y chromosome and chromosome analysis should be done as soon as possible. Many of the patients with CAH will be deficient in mineralocorticoids in addition to corticosteroids. Without prompt diagnosis and treatment life-threatening shock may develop due to dehydration and salt loss. All of the other listed options are reasonable tests for the evaluation of disorders of sex development, but will only be performed after CAH is ruled out.

Answer 58

3 Oral contraceptive pills (OCPs) significantly increase the production and release of sex hormone binding globulin (SHBG) by the liver. The increased SHBG subsequently lowers serum free testosterone by irreversible binding. Low levels of circulating free testosterone can cause a significant decrease in sexual desire/libido. While estradiol may decrease with OCPs, the effect is less striking on libido than the effect of a lower serum testosterone. Progesterone levels may actually increase with some OCPs.

Answer 59

5 Rb mutations (Retinoblastoma Protein) are found in approximately 30% of bladder tumors and are correlated with a higher stage disease at time of diagnosis and decreased patient survival. Flow cytometry has not been found to be of more clinical value than conventional cytology in determining tumor recurrence. Low grade tumors are usually diploid, bladder tumors with triploid to tetraploid will be found to have unfavorable pathologic characteristics and a poorer prognosis. Interesting patients with pure tetraploid expression have a more favorable prognosis than those of patients with triploid to tetraploid tumors but worse than diploid tumors. Both tumor size and negative random biopsies have a dramatic impact on progression rate but less on recurrence rate. In patients with a well or moderated differentiated non-invasive bladder cancer, the factor which best predicts the absence of tumor recurrence is a post TURBT negative cystoscopy at three months. If no tumor is present at three months, there is an 80% chance of no further tumor recurrence.

Answer 60

1 Although 65% of sodium chloride and water are reabsorbed in the proximal tubule, the intraluminal fluid remains iso-osmotic. Urinary concentration takes place as the tubular fluid flows through the medullary collecting ducts. The medullary interstitial hyperosmolarity in the presence of normal plasma concentrations of ADH causes water to diffuse out of medullary collecting ducts into the interstitial fluid and then into the medullary blood vessels. High ADH levels produce a more concentrated urine and low levels produce a more dilute urine.

Answer 61

5 Cross-sectional imaging, especially CT scan, has become the imaging modality of choice to demonstrate a vesicoenteric fistula. CT or MRI scans may localize the fistula track as well as the involved segment of bowel. The triad of findings on CT that are suggestive of colovesical fistula consists of (1) bladder wall thickening adjacent to a loop of thickened colon, (2) air in the bladder (in the absence of previous lower urinary tract manipulation), and (3) presence of colonic diverticula. Cystoscopy has the highest yield in identifying a potential lesion, with some type of abnormality noted on endoscopic examination in more than 90% of cases. However, the findings on cystoscopy are often nonspecific and include localized erythema and papillary or bullous change; a definitive diagnosis by cystoscopy can be made in only 35% to 46% of cases. This patient has clear evidence of a vesicoenteric fistula and further diagnostic studies are not indicated. Should she be a poor surgical risk, long-term antibiotics could be used. Definitive colonic resection of presumed diverticulosis and repair of fistula should occur with exploratory laparotomy. General surgery may wish to proceed with colonoscopy/barium enema to evaluate the extent of the affected segment or rule-out malignancy.

Answer 62

2 Although the histological diagnosis is seminoma, the elevated alpha-fetoprotein is indicative of a non-seminomatous testis tumor, and the patient should be managed as such. The orchiectomy specimen should be re-evaluated in detail to look for an additional germ cell elements. Given the findings on the CT scan, this patient has a clinical Stage IIB tumor. Based on the data available in the literature, it appears these patients are best served with initial chemotherapy rather than RPLND following the inguinal orchiectomy. The most widely utilized regimen today is three cycles of bleomycin, etoposide (VP-16), and cisplatin. If residual nodal tissue is evident after the multidrug chemotherapy, surgical excision is recommended. With the evolution of effective multi-drug regimens, radiation therapy is no longer utilized in the management of Stage IIB non-seminomatous testis tumors.

Answer 63

3 The patient has pathologic phimosis that does not allow adequate urinary drainage. Observation is only appropriate in the setting of physiologic phimosis in which the foreskin is not retractable due to normal physiologic adhesions, as opposed to pathologic phimosis, which is development of a dense fibrotic ring from chronic inflammation. Treatment of pathologic phimosis with a topical steroid ointment (0.05% betamethasone) is effective in up to 90% of cases in relieving the phimosis and allowing adequate retraction of the foreskin. If the patient had more acute problems such as severe balanitis or more obstructive voiding symptoms then surgical intervention with a dorsal slit or circumcision may be appropriate. Sitz baths alone are unlikely to rectify the problem.

Answer 64

2 Concomitant use of alpha-blockers and PDE-5 inhibitors can cause hypotension. When tadalafil is coadministered with an alpha-blocker, patients should be stable on alpha-blocker therapy prior to initiating treatment with tadalafil, and tadalafil should be initiated at the lowest recommended dose. Conversely, when starting an alpha-blocker the lowest dose of either agent should be used and they should not be taken at the same time. There is no need to stop tadalafil in this patient or switch to intracorporal injections if he has been successful on oral therapy. Of all the choices, decreasing to the lowest effective dose of tadalafil (10 mg for use as needed, or 2.5 mg/day for once daily use) would be recommended for this man.

Answer 65

2 Approximately 10-20% of patients who have had a bilateral adrenalectomy for Cushing's Syndrome later develop pituitary tumors that are almost always chromophobe adenomas (Nelson's syndrome). Progressive hyperpigmentation (due to melanocyte stimulating hormone release by corticotropic releasing hormone), headaches, and visual disturbances are due to the expanding adenoma that is diagnosed by MRI or CT scans of the sella turcica. Pituitary basophilic adenoma that was initially postulated by Cushing as causing the syndrome named for him has, in fact, rarely been a factor. Addison's disease describes primary adrenal insufficiency not as a result of bilateral adrenalectomy. Excessive cortisone replacement would result in a Cushingoid appearance (purple striae, buffalo hump, central obesity). Excessive ACTH production is not the end result of bilateral adrenalectomy. Although, increased skin pigmentation could be a result of ectopic melanocyte stimulating hormone secretion the other symptoms would not.

Answer 66

3 When the bladder dome is brought out for the vesicostomy, it effectively immobilizes the posterior wall of the bladder, preventing its prolapse out the vesicostomy stoma. The bladder dome can be reliably identified by seeing and dividing the urachal remnant. Resecting bladder tissue is contraindicated to facilitate future undiversion. The other possibilities will not prevent prolapse if the vesicostomy is performed on the anterior wall of the bladder.

Answer 67

2 A hypercoagulable state can occur in the nephrotic syndrome with urinary loss of the natural anticoagulants: antithrombin III, protein C, and protein S. Hyperhomocysteinemia is common in ESRD, and has been associated with thrombophilia. Antiphospholipid antibodies are found in 30% to 50% of patients with systemic lupus erythematosus, a cause of ESRD. Loss of antithrombin III and increased antiphospholipid antibodies increase the risk of thrombosis of renal allografts, dialysis access devices, and post-operative thromboembolic events. Thus, anticoagulation should be considered in these patients.

Answer 68

1 Rash occurs in 9% of patients receiving mitomycin C instillations, and may represent a contact dermatitis. Chemical cystitis has been reported in 6-41% of patients managed with this agent. The molecular weight of mitomycin C is so high that little is absorbed and myelosuppression is rare. A contracted bladder is also rare after mitomycin C treatment. Flu-like symptoms, which are commonly seen after BCG and interferon therapy, are uncommon after intravesical chemotherapy.

Answer 69

5 DDAVP causes retention of free water. Intravenous fluids should be iso-osmotic, and oral fluids should not be pushed, but taken according to thirst. Dangerous hyponatremia can otherwise be induced by the administration of hypoosmotic fluids during surgery, or by overencouraging oral fluids postoperatively.

Answer 70

3 Men successfully treated for prostate cancer and suffering from symptomatic hypogonadism may become candidates for androgen therapy, if there is no evidence of residual cancer after a prudent interval. The risks and benefits must be clearly understood by the patient. Close follow-up is required. Phosphodiesterase inhibitors may be used for first-line therapy of erectile dysfunction, but do not adequately address systemic manifestations of hypogonadism. In hypogonadal men, combined treatment has been reported. Yohimbine is not recommended for the treatment of erectile dysfunction.

Answer 71

3 This patient is elderly, has compromised medical and renal status and probably has a distal ureteral urothelial carcinoma. While optimal therapy in a younger, healthier patient would be distal ureterectomy and reimplantation, this patient would be well-served with endoscopic management. In the setting of subcentimeter lesions such as this one initial ureteroscopic ablation with followup ureteroscopy and surveillance is likely to be associated with equivalent control rates to distal ureterectomy and would avoid major abdominal surgery in this patient with heart failure.

Answer 72

2 When an intestinal patch will not reach the deep pelvis in a tension free manner, the first step should always be aggressive mobilization of the root of the mesentery. When this fails to achieve the desired length, transverse incisions of the peritoneum should be performed on both sides of the mesentery in a step wise fashion. This can result in significant lengthening of the mesentery. Ligation of vessels should only be done as a last resort to avoid vascular compromise to the bowel segment. Psoas hitch has also been described, but will not help move the apex of the sagittal incision by the bladder neck which is fixed. Reconfiguration will not gain more length and closure of the anterior bladder wall will risk the development of an hourglass deformity.

Answer 73

5 This patient clearly demonstrates an early prosthetic infection manifested around the scrotal pump. Treatment of a prosthetic infection with antibiotics usually results in clinical improvement but is almost never the definitive treatment and the infection will recur. This is due to microorganisms within a biofilm that is adherent to the device and the inability to sterilize the device or the biofilm once these organisms are present. When a prosthetic infection is present, all components of the prosthesis should be removed. If they are removed a new device should be replaced as soon as is feasible (within six to eight weeks) to decrease the amount of fibrosis and significant penile shortening which will occur. Mulcahy introduced the concept of immediate prosthesis salvage for infection which has been able to salvage as many as 85% of these patients and prevent penile shortening. His protocol involves removal of all prosthetic components followed by irrigation with seven antibacterial solutions. Others have reported on using different numbers and types of solutions. Mechanical irrigation and removal of the biofilm appears to be the key principle of this technique. A new device is implanted immediately after irrigation, and the patient is prescribed antibiotics. When salvage procedures are successful, they maintain penile size and correct the problem with only one operation.

Answer 74

5 It is important to know the electrolyte content of the fluid from the various bowel segments in order to replace abnormal fluid losses from these segments. Serum electrolyte complications and the type of electrolyte abnormalities that occur are different, depending on the segment of bowel used. If stomach is employed, a hypochloremic metabolic alkalosis may occur. If jejunum is the segment used, hyponatremia, hyperkalemia, and metabolic acidosis occur. If the ileum or colon is used, a hyperchloremic metabolic acidosis ensues. Hypokalemia and total-body depletion of potassium may occur in patients with urinary intestinal diversion. This is more common in patients with ureterosigmoidostomies than it is in patients who have other types of urinary intestinal diversion. The use of ureterosigmoidostomies has decreased significantly. It has been shown that ileal segments exposed to high concentrations of potassium in the urine reabsorb some of the potassium, whereas colon is less likely to do so. Thus, those with ileum interposed in the urinary tract likely blunt the potassium loss by the kidney, whereas those with colon do not, thus explaining why patients with ureterosigmoidostomies and ureterocolonic diversions are more likely to have total-body potassium depletion.

Answer 75

4 The history suggests intermittent UPJ obstruction and the associated Dietl's crisis. Dietl's crisis is intermittent abdominal pain associated with nausea and vomiting following an episode of high fluid intake. Although a renal scan with Lasix is used in an attempt to prompt the crisis, it may on occasion be falsely negative. In these patients, it is best to repeat a renal ultrasound at the time of pain and compare this to a baseline renal ultrasound taken when the patient was asymptomatic. If increased hydronephrosis at the time of symptoms is present, it is diagnostic and the pyeloplasty will be curative. Placement of a double J stent in this patient population is not usually helpful since the discomfort of the stent will usually preclude its diagnostic usefulness. A Whitaker test is invasive and usually reserved to evaluate for the presence of obstruction in a hydronephrotic kidney with poor renal function, i.e., kidney \< 25% differential function, or in a patient where the serum creatinine two times elevated for age or creatinine of greater than or equal to 2 mg/dl in the adult, in these later circumstances, renal scans will usually be falsely positive for obstruction due to poor renal function. A VCUG will not be helpful in this patient. Even if VUR is present, it is not the source of the patient symptoms. MR urogram and a noncontrast CT scan are not effective or useful on asymptomatic patients.

Answer 76

1 During a vaginal approach to a high riding post-hysterectomy fistula, a peritoneal flap is preferred. It is relatively easy to raise a well vascularized flap of peritoneum in this location. A Martius flap would be very difficult to mobilize to that location in the vagina without compromising the blood supply. An omental flap is occasionally useful from a vaginal approach if it had previously been secured in the pelvis from prior surgeries. A gracilis flap can be utilized but is typically not necessary for vesicovaginal fistulae. A labial myocutaneous flap can be utilized particularly if there is significant foreshortening of the vagina or loss of vaginal mucosa.

Answer 77

1 Drugs which are excreted by the kidneys unchanged may be resorbed by the intestinal mucosa in urinary diversions, leading to toxic serum levels. Phenytoin is the only drug listed excreted into the urine unchanged and associated with toxicity in the setting of a urinary diversion. Other commonly used drugs that can be reabsorbed include methotrexate, lithium carbonate, and theophylline.

Answer 78

4 Nephrogenic systemic fibrosis (NSF) is a disorder characterized by tissue fibrosis that primarily occurs in dialysis patients following the administration of gadolinium contrast for radiologic studies. The other distractors listed: anaphylactic reaction, nephrotoxicity (patient is already on dialysis), pruritus and congestive heart failure do not occur more frequently following gadolinium than iodinated contrast agent. Studies suggest a strong association between the use of gadolinium based MRI contrast agents and the subsequent development of NSF in patients with renal disease. Gadolinium based MRI contrast agents are chemical chelates with the gadolinium ion bound by a linear or cyclic molecule. Since free gadolinium ions are toxic and poorly excreted, safety completely rests on the ability of the chelate molecule to prevent gadolinium release. The kidneys solely excrete these agents and their half-life prolongs from one to two hours to over 30 hours with severe renal dysfunction. Renal failure allows a situation where gadolinium based MRI contrast agents reside within patients for long periods of time potentially allowing for toxic levels of free gadolinium ions to build-up, deposit in tissues, and subsequently lead to fibrosis. Therefore, patients in ESRD requiring dialysis are at a greater risk of NSF.

Answer 79

3 Sildenafil has been very effective in treating pulmonary HTN in infants and adults and was approved by the FDA in 2005. Many multi-institutional studies have demonstrated its safety and efficacy in this population. Doses for treatment of pulmonary HTN are much higher than doses used to treat erectile dysfunction (po - 100 mg TID in children and adults, IV 1.2 mg/kg I.V.). This has led to a higher incidence of adverse events including dizziness, headache, flushing, rhinitis and prolonged erection. There have been several reports of prolonged erection in children using high I.V. doses. These patients have responded to simply lowering the dose of sildenafil. This patient has shown an excellent response to treatment with I.V. sildenafil (since he has been successfully weaned off inspired nitric oxide) of his life-threatening pulmonary HTN and it should be continued. Observation is not appropriate with a prolonged erection of this type. No data is available on either switching to oral administration or to a different PDE5 inhibitor.

Answer 80

2 A marked increase in serum PSA after a nadir within six months of external beam XRT is a sign of persistent local or occult metastatic prostate cancer and has a poor prognosis. Radiation induced cellular injury or prostatitis may cause a minor rise in PSA which usually returns to normal within a few weeks. A bounce can be defined as a rise greater than 0.2 ng/ml followed by a durable decline and is especially common after brachytherapy, where it is reported to occur in 24% to 35% of men. These can start any time from 9 to 30 months after brachytherapy with the majority of patients having a cumulative PSA rise of not more than 2 to 3 ng/ml. Prostatic infarct is rare following radiation therapy for prostate cancer, and would likely be associated with a significantly elevated PSA.

Answer 81

3 This infant has an obstructed upper pole ureter in a solitary kidney and suffered urosepsis. Surgical intervention is indicated. Her age, severe pulmonary and cardiac disease makes all upper abdominal surgery unattractive. Since she has a significant portion of her renal function in the upper pole a heminephrectomy is incorrect. Anastomosis of the massively dilated upper pole system to the normal lower pole system is technically difficult either at the level of the renal pelvis or the ureter. Percutaneous nephrostomy tubes can be a short term-answer in a critically ill child but they have complications including chronic infection, calculus formation, and displacement. Tapered reimplantation in a child of this age is technically challenging because of the small bladder. The best treatment is a cutaneous ureterostomy that will allow adequate drainage and prevent infection until definitive surgery is safe. It will also allow the dilated upper pole system to decompress and reconfigure the ureter.

Answer 82

5 Off-label onabotulinum toxin injection and augmentation cystoplasty place the patient at high risk for needing to perform CIC, which is not feasible in a patient with poor manual dexterity. Sacral neuromodulation is not FDA-approved for patients with neurogenic bladder nor can patients with an implanted neuromodulator undergo MRI, a study that has a high likelihood of being necessary in a patient with MS. The best choice for this patient is an ileal conduit. When possible, chronic urethral catheter placement should be avoided as it can result in significant urethral loss, UTIs, stones, and an increased risk of bladder malignancy. While not the recommended treatment, if long-term catheter drainage is chosen, a suprapubic tube is preferable to a urethral catheter, with careful long-term follow-up required.

Answer 83

2 The negative Hounsfield units on the CT scan indicate the presence of fat in the tumor, showing that this is a renal angiomyolipoma which has bled acutely. Angiographic embolization is often successful in these tumors, can be performed quickly without the need for general anesthetic, and can usually preserve the normal portion of the kidney. If a patient has tuberous sclerosis, bilateral disease, preexisting renal insufficiency, or other medical or urologic disease that could affect renal function in the future, selective embolization should be considered as the treatment. An alternative would be lower pole partial nephrectomy, once the patient is stabilized, but not in the acute setting as often times radical nephrectomy would be required. This would put this patient at significantly increased risk of dialysis. Laparoscopic nephrectomy would be very difficult in the face of recent acute hemorrhage. Radio frequency ablation should not be used for such a large tumor.

Answer 84

1 Priapism occurs in males with all forms of sickle cell anemia but most commonly the sickle cell disease. When presenting in childhood it may be associated with impotence later in life. A precipitating event should be searched for, such as drug usage, medications used for impotence (not in the pediatric population), infection, trauma, or psychoactive medications. Hydration and opioid analgesic are the mainstays of management of all forms of sickle cell pain. Oxygen is indicated when the patient is hypoxic. Erection results from relaxation of the smooth muscles of arterioles and trabeculae in the corpora, and detumescence is the result of smooth muscle contraction, opening emissary veins and increasing venous drainage. Therefore, detumescence should be facilitated by alpha-adrenergic agonists such as pseudoephedrine (a pure alpha-adrenergic agent). These agents induce contraction of the smooth muscle of the trabecular arteries of the cavernosa, forcing blood out of the cavernosa and promoting detumescence. Exchange transfusions are used after conservative methods mentioned above fail. Aspiration/injection or invasive shunts are used only if detumescence is not achieved by pharmacological methods.

Answer 85

2 Voiding dysfunction in men with Parkinson's disease can be a result of a multitude of factors, including outlet obstruction related to the prostate, detrusor-striated sphincter pseudodyssynergia, and rarely true dyssynergia. While detrusor overactivity is the most common urodynamic finding in this population, poor detrusor contractility or areflexia may also be seen. Although chronic suppressive antibiotics, tamsulosin, and CIC are not unreasonable options, urodynamics studies should be performed prior to proceeding with any therapy, no matter how simple, to ensure that the proper course is being taken.

Answer 86

1 The peak age of onset of testicular cancer is between 25 and 35 and cryptorchidism is the only know risk factor for testicular cancer. However the risk of developing a testis tumor in an undescended testis drops dramatically after age 30. It has been calculated that the risk of dying from testis cancer after age 32 is outweighed by the risk of surgical mortality, though others have suggested a cutoff of 50. At age 60, this patient should be reassured and does not require serial ultrasounds.

Answer 87

2 Spinal cord abnormalities, including tethered cord or thickened or fatty filum terminale and lipoma have been noted in 20-50% of patients with imperforate anus. The severity of the lesion is proportional to the severity of the rectal lesion. In this case, the patient has a high-imperforate anus. VCUG reveals trabeculation, VUR into one kidney, and incomplete bladder emptying - a collection of findings for possible neurogenic bladder dysfunction. The best test is an MRI scan to rule-out spinal cord lesions since the kidneys are presently normal and the bladder has some subtle findings. Due to ossification of the spine a spinal ultrasound cannot rule-out a tethered spinal cord after three months of life. Vesicostomy, CIC, and antimuscarinic and alpha-blocker medications are premature at this point without formal diagnosis of neurogenic bladder and urodynamic study.

Answer 88

1 This patient has symptomatic stress urinary incontinence (SUI), though none is noted on exam. She should not be treated invasively for SUI without documentation on exam. A positive pad test could be the result of urgency leakage, even though she does not report it, as could leaks reported on a voiding diary. She should return for a full bladder stress test done supine and repeated standing if necessary. If that remains negative, urodynamics could be offered to try to better delineate her leakage. VCUG will not add to the diagnostic evaluation in this case, as leakage noted during that test is still not diagnostic of SUI. Antimuscarinics should not be offered in the presence of primarily SUI complaints.

Answer 89

2 Previously, prior pelvic radiation therapy was an absolute contraindication to orthotopic neobladder. However, recent reports have demonstrated that this can be a safe and effective form of diversion in properly selected patients. Astute intraoperative tissue assessment and determination of the condition of the urethra, ureters, and bowel must be done to limit complications and to provide the best possible clinical outcomes. In this case, it would be safe to proceed with orthotopic neobladder. Distal ileum is preferred to right colon in this setting. Right colon is less mobile and more difficult to detubularize than ileum. Preoperatively, the patient needs to be counseled that he is at higher risk for urinary incontinence.

Answer 90

1 This patient has a picture equivocal for primary hyperparathyroidism with hypercalciuria, serum calcium at the upper limits of normal and a high, but normal serum PTH value. A thiazide challenge would help to differentiate renal hypercalciuria from primary hyperparathyroidism. After treating her with a thiazide diuretic for two weeks, her serum calcium and PTH should remain within normal limits and her urinary calcium should return to normal if she has renal hypercalciuria. If, however, she has true hyperparathyroidism, she would become overtly hypercalcemic and her serum PTH would become elevated with no significant change in the urinary calcium excretion. The other agents will not help elucidate her underlying metabolic abnormalities.

Answer 91

3 After renal trauma, the likelihood of renal exploration, renorraphy, and nephrectomy is associated with the grade of injury. For example, Grade 4 injuries have a 64 fold higher likelihood of needing nephrectomy than a Grade 1 injury. New literature shows that for grade 3 and 4 injuries, medial hematoma, hematoma \> 3.5 cm in thickness and the presence of a vascular contrast blush are associated with increased risk of bleeding and need for intervention. The presence of such findings should alert the urologist to the potential need for angiography and selective embolization of segmental vascular injuries. While urinary extravasation and devitalized fragments increase the risk of urinoma formation, they are not associated with higher rates of bleeding. Neither location of laceration or mechanism of injury predict complications independent of grade.

Answer 92

1 The patient exhibits an absolute indication of nephron sparing surgery with a serum creatinine of 1.9 mg/dl which translates into a estimated GFR of 26 ml/min. This patient is in need of retaining as much functional renal parenchyma as possible. This coupled with the fact that she has exhibited an indolent chromophobe subtype of renal cancer is a strong indication to not perform further cancer eradicating procedures. In addition, even in the presence of a positive focal margin there is a very low risk of renal cancer relapse as demonstrated by multiple retrospective data analysis of this scenario. Energy-based therapies in the renal hilar bed would be associated with a high rate of renal unit loss.

Answer 93

5 All children with \> 1 proteinuria on multiple occasions should be evaluated, starting with a UA and first morning spot protein and creatinine ratio. The child must void before retiring and remain supine until the first morning urine sample is obtained. If the ratio is \< 0.2, a diagnosis of orthostatic proteinuria is made and no further studies are needed. If other abnormalities are noted on the UA and/or the first morning protein and creatinine ratio is \> 0.2, a complete history and physical, including blood pressure, is suggested. Laboratory evaluations, including serum albumin, creatinine, cholesterol, electrolytes, and a 24-hour urine for protein and creatinine and creatinine clearance are obtained. A renal sonogram should be performed. Complement levels (C3, C4) antinuclear antigen (ANA), and serology for hepatitis B and C are indicated. HIV testing should be considered.

Answer 94

3 In men with azoospermia, 7% will be associated with Y chromosome microdeletions. Classically, these patients will be found to have azoospermia or severe oligospermia with an elevation in FSH. The microdeletions occur in the long arm of the Y chromosome and are designated as AZFa (proximal), AZFb middle, and AZFc distal. The most common deletion is AZFc. About 75% of men with AZFc deletions have sperm on testicular biopsy. Sperm retrieval from men with complete AZFa or AZFb deletions have not been successful. The success of testicular sperm retrieval has not been correlated with FSH or testosterone level. Seminal volume does not reflect spermatogenic potential and has no relationship to the success of sperm retrieval. The absence of the vas deferens may be associated with obstructive azoospermia but these patients should have a normal FSH whereas this patient has an elevated FSH indicating non-obstructive azoospermia.

Answer 95

3 This man, by virtue of his age and androgen deprivation therapy, is at increased risk for osteoporosis. The consequence of osteoporosis is an increase in bone fragility and a susceptibility to fracture. Androgen deprivation therapy (ADT) increases the risk of osteoporosis and is related to the duration of therapy. Compared to age-matched controls, men on ADT have 6.5% to 17.3% higher bone loss. Furthermore, the risk of non-pathologic fracture with ADT is 4% at five years and 20% at ten years. DEXA scan is the gold standard for diagnosis of osteoporosis, and is reported as compared to young adults (T-score) and age-matched (Z-score) controls. The treatment initially includes increasing physical activity on weight bearing joints and the addition of both Vitamin D and calcium. Since this patient has no clinical evidence of disease progression, there is no indication for additional treatment. MRI scan reveals only a nonpathologic fracture and PSA is undetectable; this combination obviates the need for a bone scan

Answer 96

4 The creatinine in a newborn is reflective of maternal renal function and is not necessarily representative of the degree of renal impairment. In usual circumstances, serum creatinine will reflect the child's renal function by day 7-10. Long term renal function in children with PUV is best predicted by the nadir creatinine at one year of age. If the nadir creatinine is less than 0.8 mg/dl at one year of life, this is a good prognostic sign for retained renal function that will be able to be maintained into adulthood. By 34 weeks gestational age, nephrogenesis is complete and will not affect the level of the creatinine. Sodium reabsorption issues cannot be predicted until the degree of true renal functional impairment is better defined.

Answer 97

5 Ureteral peristalsis does not require autonomic input. It originates and is propagated from the intrinsic smooth muscle pacemaker sites in the minor calyces of the collecting system. The kidneys do receive preganglionic sympathetic input from T8 to L1 and postganglionic fibers from the celiac and aorticorenal ganglia, as well as parasympathetic input from the vagus nerves, however the role of ureteral autonomic input is unclear. This explains why denervated or transplanted kidneys maintain ureteral peristalsis.

Answer 98

2 Prostatic ductal carcinoma is an adenocarcinoma that arises in prostatic ducts. It should be graded as a Gleason 44 since it shares a cribriform pattern and is associated with high grade disease and recurrence. It should be treated similarly to other high grade adenocarcinomas with combination hormonal therapy/ radiation therapy or radical prostatectomy or cryotherapy or primary hormonal therapy depending on patient age, fitness and preference. Like other carcinomas, ductal carcinoma arises more commonly in the peripheral than the transitional zone.

Answer 99

3 This boy has the classic triad of Leydig cell tumors: precocious puberty, testis mass, and elevated 17-ketosteroid levels. Pituitary lesions may also cause precocious puberty except LH and FSH will be elevated in a prepubertal male. These tumors must be differentiated from hyperplastic nodules of CAH which occur when steroid replacement is inadequate. Although both entities have elevated urinary 17-ketosteroids, only CAH due to the 21-hydroxylase deficiency will cause an elevation in urinary pregnanetriol levels. Glucocorticoid replacement will cause regression of the hyperplastic nodules of CAH. Simple and radical orchiectomy is often performed but not preferred. These tumors are generally benign and preservation of testicular tissue with testis sparing surgery is recommended.

Answer 100

2 Sterilization, whether by steam under pressure, ozone, ethylene oxide gas or other methods involves the complete destruction of all microbial life, including bacterial spores. Disinfection uses thermal or chemical destruction of pathogenic and other types of microorganisms, and is less lethal than sterilization. High-level disinfection (HLD) cannot kill large numbers of bacterial spores unless they are exposed for an extended time period. Intermediate-level disinfection inactivates M. tuberculosis, vegetative bacteria, most viruses, and most fungi, whereas low-level disinfection cannot be relied upon to kill resistant microorganisms such as tubercle bacilli or bacterial spores.

Answer 101

1 The patient described above has the classic symptoms and signs of acute adrenal insufficiency. The most common symptoms and signs of acute adrenal insufficiency occurring in the setting of clinical deterioration are fever, nausea/vomiting, abdominal or flank pain, hypotension, abdominal distention, lethargy/obtundation, hyponatremia, and hypokalemia. The urologist should have a high index of suspicion for acute adrenal insufficiency following radical nephrectomy and the degree should be heightened in a patient receiving sunitinib as it may contribute to the condition. Physicians are advised to monitor for adrenal insufficiency in patients treated with sunitinib who experience stress such as surgery. As this was an upper-pole mass, the ipsilateral adrenal may have been removed or devascularized as well. Emergency treatment of adrenal crisis is normal saline fluid resuscitation, and dexamethasone sodium phosphate injection (Decadron, 4 mg I.V.). Stat serum electrolytes, glucose, cortisol, and plasma ACTH are obtained. A short ACTH stim test to confirm the diagnosis of adrenal insufficiency is then performed. Supportive measures are provided as needed. Mineralocorticoids are unnecessary and ACTH is not useful. CT scan would be indicated if the patient did not respond to fluid and steroids and adrenal insufficiency is ruled out. Angiography and surgical exploration are also premature given the clinical scenario suggestive of adrenal crisis. I.V. desmopressin would not be first line treatment in this patient with adrenal crisis, but could be indicated if hypotension was refractory to fluid resuscitation and steroids.

Answer 102

3 Measuring renal function in patients with intestinal diversion may be difficult. Most parameters of renal function will be affected by the intestinal absorption of various substances in the urine, including creatinine and urea, as well as secretion of alkalinizing substances and alteration in the osmotic content. Sodium handling in ileal segments is not markedly altered as ammonium substitutes for sodium in the Na/H antiporter in the bowel lumen.

Answer 103

3 Men with Klinefelter Syndrome are at increased risk for the development of breast cancer. Approximately 80% of cases are estrogen receptor positive, therefore any treatment that increases estrogen levels is contraindicated unless the patient is cured of breast cancer. This patient has symptomatic hypogonadism which would benefit from an increase in serum testosterone but he was recently treated for breast cancer. In men a portion of testosterone is converted to estradiol, primarily in adipose tissue. Aromatase inhibition will decrease conversion of testosterone to estrogen thereby raising testosterone levels while at the same time decreasing estrogen levels. This is safe in men with breast cancer. Phosphodiesterase inhibitors are indicated for erectile dysfunction which this patient does not complain of. Estrogen therapy has no role in treating these symptoms in men and risks stimulation of breast cancer cell growth. HCG will increase testicular production of testosterone. The increased peripheral testosterone levels from either HCG or testosterone therapy will result in increased estrogen levels due to the peripheral conversion to estrogen. Therefore these are inappropriate therapies in men with breast cancer. In Kleinfelters, patients without breast cancer, standard treatment of hypogonadism with testosterone replacement is safe.

Answer 104

4 The treatment of men with isolated lymph node metastasis at the time of prostate cancer surgery has been controversial. The use of adjuvant XRT for adverse pathologic characteristics at the time of prostatectomy has been recently evaluated in two large randomized clinical trials. However, patients with lymph node metastasis, such as patients here, were not included in this trial, and it is generally felt that such individuals are at risk of systemic rather than local recurrence. ECOG 3807 evaluated the use of immediate hormonal ablation versus observation in men with isolated lymph node metastases noted on final pathology after radical prostatectomy. The patients treated with immediate therapy had improved overall and cancer-specific survival relative to men undergoing initial observation. No trial has been performed showing an advantage of any chemotherapy treatment in the adjuvant setting. The advantage of short-term androgen deprivation therapy in this setting has not been established.

Answer 105

1 This child has the symptoms of dysfunctional voiding and cystitis. It is not uncommon for children with dysfunctional voiding habits to develop UTIs, but unless they have VUR, they are unlikely to have pyelonephritis, which is usually associated with a fever. In this setting, it is unnecessary to perform another VCUG or renal scan because the infection was not febrile in nature. Urodynamics are likely to be normal, and the emphasis should be on bladder retraining, to avoid any further episodes. While prophylactic antibiotics may be needed to keep these children infection free while they retrain their bladders, it is preferable to keep them off prophylactic antibiotics if possible. Constipation is often present and should be concurrently treated.

Answer 106

2 Bacteria may convert urinary nitrates into nitrites and this may be used as evidence of UTI. Gram negative bacteria commonly do this, while gram positive species generally do not. One very important exception is Pseudomonas, which does not contain the enzymatic machinery to make this conversion. Thus, a negative nitrite by urinary dipstick in this patient with symptoms and other UA finding suggesting UTI should likely be treated presumptively pending culture and Pseudomonas is one of the very important, aggressive pathogens that must be considered in this circumstance.

Answer 107

5 This patient has not been adequately staged which makes the choice of an appropriate therapy difficult. According to the AUA Guidelines on superficial bladder cancer, in the absence of muscularis propria, data suggest that 20 to 40% of patients will have residual tumor and/or unrecognized muscle invasive disease. Therefore, repeat resection is considered a standard in this setting. All other therapeutic options would be inappropriate at this point because the patient has not been completely staged.

Answer 108

2 This patient has Turner Syndrome. These girls can be recognized by their typical physical findings including short stature, webbed neck, and shield chest. Girls with the 45 XO karyotype usually exhibit all the stigmata of the syndrome. Patients with the 45 XO/46 XY karyotype are at increased risk for dysgerminoma and gonadoblastoma and require gonadectomy. Horseshoe kidney occurs with increased prevalence in patients with Turner syndrome and a renal ultrasound is warranted. VUR, renal agenesis and vaginal agenesis are not associated with Turner syndrome. UPJ obstruction may occur in association with horseshoe kidney, but is not seen with increased frequency in Turner syndrome.

Answer 109

3 The goal of potassium citrate therapy is to correct the acidosis associated with chronic diarrheal states. Although in many instances potassium citrate tablets appear in the stool. Although the medication is being absorbed, switching to a liquid preparation is recommended in these patients. The slow release approach is mitigated in these cases. Baking soda and the dosing measures would not achieve the best outcome.

Answer 110

1 The Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial randomly assigned 76,693 men to receive either annual screening (38,343 subjects) or usual care as the control (38,350 subjects). Men in the screening group were offered annual PSA testing for six years and DRE for four years. After seven years of follow-up, the incidence of prostate cancer was higher in the screened population; the number of prostate cancers per 10,000 person-years was 116 (2820 cancers) in the screening group and 95 (2322 cancers) in the control group. Prostate cancer survival was similar between study groups; the incidence of death per 10,000 person-years was 2.0 (50 deaths) in the screening group and 1.7 (44 deaths) in the control group. The numbers of subjects with advanced (stage III or IV) tumors were similar in the two groups, with 122 in the screening group and 135 in the control group, though the number of subjects with a Gleason score of 8 to 10 was higher in the control group (341 subjects) than in the screening group (289 subjects). Quality of life was not assessed. Thus, in this US trial, screening did improve detection rate; however, at a median follow-up of seven years, there was no difference in survival between the two groups.

Answer 111

4 One of the most frequent causes of intermittent gross hematuria in children is Berger's disease or IgA nephropathy. While the disease may be more benign in children, occasional cases will progress to renal failure, making its recognition important. These patients should be followed with serum creatinine and 24-hour urine for creatinine and protein. If these indicate mild and stable disease, biopsy is not required. Hemolytic uremic syndrome is the triad of hemolytic microangiopathic anemia in association with thrombocytopenia and renal insufficiency. Henoch-Schonlein purpura (HSP) can present with acute glomerulonephritis and can evolve into IgA nephropathy. HSP is a systemic vasculitis which commonly affects the skin, GI tract, joints and can affect the kidney. Membranous glomerulonephritis (MGN) is the most common cause of nephritis in adults but seen less frequently in children. The pathologic hallmark of MGN is the presence of glomerular subepithelial immune deposits on electron microscopic examination. Alport's Syndrome is an inherited disorder of glomerular basement membrane due to type IV collagen abnormality and is associated with a hearing loss. The biopsy findings will show abnormality of the glomerular vasculature.

Answer 112

4 When combined with TMP-SMX or ampicillin, aminoglycosides are the first drugs of choice for febrile UTIs. Their nephrotoxicity and ototoxicity are well-recognized; hence, careful monitoring of patients for renal and auditory impairment associated with infection is indicated. Once-daily aminoglycoside regimens have been instituted to maximize bacterial killing by optimizing the peak concentration to minimal inhibitory concentration ratio and reduce potential for toxicity. Administering an aminoglycoside as a single daily dose can take advantage not only of its concentration-dependent killing ability but also of two other important characteristics: time-dependent toxicity and a more prolonged post-antimicrobial effect. The regimen consists of a fixed 7 mg/kg dose of gentamicin or 5-7 mg/kg tobramycin. Subsequent interval adjustments are made by using a single concentration in serum and a nomogram designed for monitoring of once-daily therapy. Antimicrobial doses are given at the interval determined by the drug concentration of a sample obtained after the start of the initial infusion. This regimen is clinically effective, reduces the incidence of nephrotoxicity, and provides a cost-effective method for administering aminoglycosides by reducing ancillary service times and serum aminoglycoside determinations. In this case the serum level of tobramycin is high and requires adjustment. Changing to q 36 hours is indicated. Decreasing the dose may lead to the same reduction in levels but with a reduction in effectiveness. Although the patient continues to have symptoms, this is common during the initial course of pyelonephritis and is not an indication at 48 hours to change antibiotic regimen.

Answer 113

3 Rarely, patients with suspected pheochromocytoma present with normal or mildly elevated plasma catecholamines. When signs and symptoms of pheochromocytoma are present and plasma catecholamines are mildly elevated, it is critical that the cause of HTN is determined. The best way to distinguish between essential HTN and pheochromocytoma in this situation is an oral clonidine test. Patients with essential HTN will experience a significant drop in plasma catecholamines, while those with pheochromocytoma will not. The clonidine test is not useful in assessing for renal artery stenosis, adrenal hyperplasia or idiopathic hyperaldosteronism.

Answer 114

5 A diverticulum of the bulbous urethra in a young male is most commonly related to dilation of a Cowper's gland duct. The ducts of Cowper's gland open into the urethra in the bulb and travel to the glands located in the urogenital membrane adjacent to the membranous urethra. These cysts have been found in 2.3% of autopsied males; however, they are rarely diagnosed clinically. Straddle injury usually is associated with stricture formation. Urethral duplication, although a possibility here, is much less common and often associated with infection. A utricle would enter the prostatic urethra.

Answer 115

2 The most likely GU injury in this patient is a prostatomembranous urethral disruption, as suggested by the type of pelvic fracture. Fractures of the pubic rami, in particular the medial inferior ramus, and pubic diastasis are independent predictors of urethral injuries. In most patients, in the absence of blood at the urethral meatus, catheterization is appropriate as the first step. However, in a high risk patient with a palpable bladder and inferior ramus fracture, a urethrogram is the easiest, most specific, and most rapid way to assess urethral injury. Upper tract imaging is not indicated in patients with pelvic fracture. Cystography may be indicated, but not before the urethra has been determined either by retrograde urethrogram or catheterization, to be intact. CT urogram is not a sensitive or specific test for urethral injury. Abdominal ultrasound may demonstrate intraperitoneal fluid but is unlikely to detect injuries to the urethra. Suprapubic cystostomy is not indicated prior to evaluation of the urethra. A gentle attempt at urethral catheterization may be appropriate prior to imaging in the unstable patient.

Answer 116

1 In multivariate analysis of a microarray of multiple RCC, certain molecular markers were independently predictive of survival in patients. Those that were predictive of longer survival included high carbonic anhydrase IX (CAIX), absent vimentin and absent p53 expression. CAIX is a von Hippel-Lindau mediated enzyme. High expression of CAIX predicts favorable prognosis. These factors were predictive independent of clinical variables.

Answer 117

2 With complete ureteral duplication, the upper pole ureter is more likely to have an ectopic insertion. VUR is more common into the lower pole segment. Reflux into the upper pole moiety alone occurs in children when the orifice is ectopic in the bladder neck or urethra. The ureter lacks trigonal support and has an inadequate submucosa tunnel. This situation occurs in less than 10% of cases of complete ureteral duplication. Ureteral duplication, incomplete or complete, occurs in 0.8% of the population. As many as 40% of cases are bilateral, but most of these are insignificant partial ureteral duplications. Bilateral ectopic insertion of the upper pole ureter with VUR into this moiety alone is very rare. The lower pole ureteral segment would not be ectopic as that would not follow the Weigert-Meyer rule (lower pole VUR, upper pole obstruction). There is no reason to suspect that the lower pole is obstructed if there is VUR into the upper pole system.

Answer 118

2 Patients with blunt injuries of the kidney have been managed successfully with observation alone even when there is evidence of urinary extravasation and preliminary imaging studies. Extravasation resolves in approximately 85% of renal injuries without the need for internal or external drainage. However, patients with persistent extravasation should be managed with optimized drainage of urine with an internal ureteral stent. This may require additional decompression of the bladder to allow complete closure of the injury to the collecting system. Percutaneous nephrostomy tube placement may be difficult in a patient without hydronephrosis and percutaneous perinephric drainage is not necessary unless there is evidence of infection or large urinoma formation. Surgical exploration and repair is excessively invasive; ten days after injury such an exploration may increase the likelihood of nephrectomy due to the difficulty of renorrhaphy in the face of significant perinephric reaction to urine leakage.

Answer 119

3 Normal serum tumor markers following chemotherapy are associated with a 10-20% chance of viable germ cell tumor and 30% probability of teratoma. Normal CT scan with no lymph node larger than 8 mm is associated with a greater than 90% chance of fibrosis at the time of RPLND. The presence or absence of bleomycin in the chemotherapy regimen is not associated with probability of response and the prechemotherapy mass size or stage is not a powerful predictor of post chemotherapy histology. Normal pre-chemotherapy tumor markers and the presence of teratoma are not predictive of fibrosis at RPLND.

Answer 120

1 The child has significant hypernatremia and hypokalemia. Most cases of hypernatremia are due to loss of water or failure to adequately replace water loss. In this case, water loss is due to diarrhea and vomiting. These extrarenal water losses are associated with a decrease in extracellular fluid volume indicating deficits in total body sodium as well as water. The proportionally greater deficiency of water than of sodium leads to the increase in the serum sodium concentration. Initial fluid replacement in this child should replace the water loss and salt losses with a hypotonic salt solution (0.25NS with 40 mEq/l KCl at 100 cc/hr) at a rate 1.5-2.0x maintenance.

Answer 121

2 Blast injury represents a complex set of events resulting in direct or indirect soft tissue damage. The initial blast can cause tissue damage, and propelled fragments can cause penetrating injuries. Falling objects or impact from blast displacing the victim's body against a stationary object usually cause blunt injuries but could also cause penetrating injuries. Additionally, victims often suffer burns from the heat discharged by the explosive device or by fire ignited by the blast. Gunshot wounds represent localized tissue damage similar to the initial blast described above. The degree of injury reflects the weapon, bullet, and distance from the projectile to the affected organ. Bullet velocity has the greatest effect on soft tissue damage; whether bullet velocity reflects tissue damage precisely is controversial. However, high-velocity weapons clearly cause extensive soft tissue damage. The greater the bullet velocity, the larger the temporary cavity created, indicating the extent of soft tissue stretch and destruction The progressive changes seen on day one post injury suggest an evolving blast injury. Minor ureteral contusions from penetrating mechanisms can be treated with stent placement. Caution must be exercised, however, as minor-appearing ureteral contusions may stricture later or break down secondary to unappreciated microvascular damage to the ureter. Thus, in this case, stenting is the next step because a more severe injury is not evident. When tissue damage appears more significant the injured portion of the ureter should be débrided and ureteroureterostomy used to repair the injury. Exceptions to this are the pelvic ureter, for which reimplantation is preferred over ureteroureterostomy due to the poor blood supply to the distal ureter. Although percutaneous nephrostomy is useful in establishing proximal diversion of urine, it is probably not yet indicated in this case; furthermore, stenting across the injured segment is strongly recommended to reduce the risk of complete obliteration.

Answer 122

2 Paratesticular leiomyosarcoma occurs most commonly during the first two decades of life. On gross inspection, these tumors appear circumscribed, but on microscopic examination they often extend well beyond the margin seen by the naked eye. Despite achieving a negative margin, local recurrence risk is significant. Because of this, the primary paratesticular tumor should be removed by inguinal orchiectomy with high ligation of the cord. Excision of the inguinal scar is also usually performed at time of orchiectomy to reduce local recurrence. Chemotherapy and radiation are reserved for patients with gross or microscopic residual disease after surgical resection. RPLND for stage I paratesticular leiomyosarcoma is not indicated.

Answer 123

4 The fetal hypogastric arteries carry de-oxygenated blood to the umbilical arteries and placenta. When the placental circulation ceases at birth, the part of the hypogastric artery distal to the superior vesical artery is converted into a solid fibrous cord which becomes the medial umbilical ligament (obliterated hypogastric artery).

Answer 124

3 The majority of patients with congenital bilateral absence of the vas deferens (CBAVD) are found to have mutations or 5T polymorphism of the CFTR (cystic fibrosis transmembrane regulator protein) gene. Men with CBAVD may have subtle pulmonary disfunction such as recurrent bronchitis and other family members may carry CF mutations, therefore the man should be offered CF testing. If the female partner has a CF mutation, the couple's children have a 50% chance of having mutations in both CF genes and developing clinical cystic fibrosis. CF testing of both partners is ideal if the couple is considering sperm retrieval and ICSI. Diagnostic testicular biopsy is not necessary since CBAVD is associated with obstructive azoospermia. Scrotal exploration will not find the vas deferens. CBAVD patients should have normal karyotypes and will not have AZF deletions of the Y-chromosome. Scrotal ultrasound will not add any useful information. While donor insemination is an option, it is not the next step if the couple is considering all options.

Answer 125

5 A recent randomized, controlled trial evaluating patients with clinical stage 1 NSGCT concludes that CT scans at 3 and 12 months after orchidectomy should be considered a reasonable option in low risk patients. This schedule was compared with CT scans at 3, 6, 9, 12, and 24 months. This less intensive CT scanning regimen is recommended for low-risk patients such as this patient. This patient does not have any high risk features (significant embryonal cell CA component and/or lymphovascular invasion). An alternative strategy to reduce radiation is to use abdominal MRI scan, although this has not been systematically studied.

Answer 126

5 The child has suffered a colonic perforation. Although rare, this complication due to a retrorenal colon is more common in patients with neurogenic bowel. The majority of these injuries can be managed nonoperatively with a double-J stent, tube drainage of the colon, low residue diet and broad-spectrum antibiotics. The tube is left in the colon for seven to ten days. If a contrast study at that time shows no evidence of extravasation or fistula formation, the tube can be removed. Open exploration is reserved for patients with intraperitoneal perforation, peritonitis, or sepsis.

2012 Flashcards

(150 cards)