2010 Flashcards

Question

Pretransplant bilateral nephrectomy is necessary for: 1. glomerulonephritis 2. polycystic kidney disease 3. medullary sponge kidney 4. diabetes 5. recurrent pyelonephritis.

Answer 1

5 Of the conditions listed, the only solid indication for pretransplant nephrectomy is the patient with a well-documented history of pyelonephritis. Pretreatment bilateral nephrectomy is most important in those patients with active infection. The hazards of active infection and immunosuppression certainly justify the risk. There is no indication for nephrectomy in the patient with glomerulonephritis. Patients with polycystic disease do not require bilateral nephrectomy prior to transplantation unless the kidneys are infected, contain abscesses or are too large. Cases of diabetes and medullary cystic disease not associated with UTI need not have pretransplant nephrectomy.

Answer 2

4 The differential diagnosis of low ejaculate volume azoospermia is ejaculatory duct obstruction, hypogonadism, vasal agenesis, ejaculatory failure, and testicular failure. Hypogonadism was excluded by a normal testosterone level and the patient has palpable vasa. Retrograde ejaculation is not present because no sperm are in the post-ejaculate urine. This patient has either testicular failure or an obstruction of the ejaculatory ducts. Seminal vesicle aspiration under transrectal ultrasound guidance will reveal numerous sperm if obstruction is present and is the least invasive method to diagnose this treatable lesion. Ejaculatory duct cannulation is difficult and thus may not diagnose the problem.

Answer 3

4 Micropapillary bladder carcinoma is a rare variant of urothelial carcinoma. As opposed to the standard form of urothelial carcinoma, intravesical BCG therapy appears to be ineffective against micropapillary variant, and therefore restaging TURBT would not change the management. Recent results suggest that the optimal treatment strategy for nonmuscle invasive micropapillary urothelial carcinoma is radical cystectomy performed before progression.

Answer 4

3 Forty-four percent of carriers of VHL disease have central nervous system lesions. VHL disease is often associated with headaches and papillary edema due to hemangioblastomas of the cerebellum. In addition, renal tumors are associated with microscopic hematuria. Spinal hemangioblastomas can occur in 24% of patients and are suspected in this individual as a cause for her neurogenic bladder.

Answer 5

5 Recurrent gross hematuria in young adults occurring after an upper respiratory infection or exercise is the classic presentation of IgA glomerulonephritis (Berger's disease). Back pain and renal colic due to clots may be associated with the hematuria can persist for days or weeks and may recur. Though the course is chronic, young patients generally have a good prognosis. Renal insufficiency develops in approximately 25% of patients, a poor prognosis is more likely in those with older age, heavy proteinuria, HTN or abnormal renal function at presentation. The pathology evident on renal biopsy is proliferative and confined mostly to mesangial cells. These changes are usually limited to either some glomeruli or lobular segments of a glomerulus. Though deposits of IgA and IgG may be present on biopsy, these findings are not pathognomonic of the disease as mesangial deposits are found in other forms of glomerulonephritis. Renal imaging or endoscopic intervention is not indicated.

Answer 6

5 Studies have shown that finasteride 1 mg PO qd has a similar effect on PSA levels as finasteride 5 mg PO qd. Therefore, the PSA must be adjusted by a factor of 2 to get the true value. In this case, the adjusted PSA is 4.8 ng/ml. Therefore, the PSA is elevated and the patient should undergo a prostate needle biopsy. Repeat PSA in 6 or 12 months is not appropriate and may result in a delay in diagnosis. Free/total PSA ratio likely will not add much additional information, as total PSA is above the threshold for biopsy. Stopping finasteride and repeating PSA again may result in delay of diagnosis.

Answer 7

1 Although less common with improved radiation techniques, radiation-induced fistulas are commonly associated with persistent or recurrent cervical cancer. Fistulas may occur during or shortly following XRT as a result of tumor necrosis in the wall of the vagina or bladder. Fistulas that develop one or more years following XRT are attributed to radiation induced endarteritis obliterans with subsequent necrosis of the vaginal and bladder wall. The most important aspect in the management of a patient with a fistula following XRT is to rule out recurrent cervical cancer. Locally recurrent cervical cancer following definitive XRT is associated with poor survival despite aggressive multimodal management. Fistula repair would not be indicated in the setting of recurrent disease.

Answer 8

5 Penicillins have proven to be the safest antibiotics for use during pregnancy. However if the patient is allergic to penicillins, they (and the cephalosporins) should not be used. Nitrofurantoin is usually safe but there is a small risk of maternal neuropathy (with long term use) and hemolysis in the fetus with relative G6PD deficiency. Trimethoprim/sulfamethoxazole is best avoided because folic acid antagonists are known teratogens. Tetracycline is contraindicated because of the adverse effects on the mother (hepatotoxicity) and fetus (tooth discoloration and dysplasia). Ciprofloxacin would be contraindicated because of its adverse effects on developing cartilage.

Answer 9

1 This patient has a detectable PSA after radical prostatectomy. This is a difficult and controversial topic. Studies have shown that many patients who experience biochemical recurrence after radical prostatectomy never experience clinical symptoms and die of non-prostate cancer related causes. There are certain predictors that allow patients with clinically meaningful recurrences to be differentiated from those who do not require immediate intervention. Specifically, PSA doubling time and Gleason score at the time of prostatectomy, in addition to margin state and pathologic stage, are important predictors of both biochemical and clinical recurrence. In this case, the patient has a low PSA with a long doubling time. In fact, many urologists would not consider this a clinical recurrence. They feel that a biochemical recurrence after radical prostatectomy should be defined as a PSA \> 0.2 or 0.4 ng/ml. In addition, there are reports of benign tissue left at the apex causing small rises in PSA that often present like this case. Given the slow doubling time, low Gleason score and favorable pathologic stage, the PSA should continue to be followed, albeit more closely and intervention should be reserved until the PSA doubling time shortens or the total PSA rises to a level unacceptable to the provider and patient. Biopsy of the prostatic bed is not appropriate, as this cannot conclusively rule-out the presence of recurrence and is associated with some morbidity. Bone and/or PET scan add little to the work-up, as it is highly unlikely that there is radiologically measurable metastatic disease at this PSA level. Intervention with either pelvic radiation or hormones should be reserved, as discussed earlier.

Answer 10

3 Persistent voiding dysfunction with urgency, frequency, and diurnal urinary incontinence in this age group warrants screening with ultrasound. This image shows a diffusely thickened bladder with the bladder wall measuring \> 5 mm (the upper limits of normal). This is a warning sign for outlet obstruction due to either an anatomic abnormality, neurogenic or non-neurogenic cause. This finding cannot be ignored. Cystoscopy can provide evidence for anatomic obstruction but would not be the recommended next step. The child should undergo a VCUG to rule-out the presence of valves. Observation, behavioral modification, and oxybutynin could be considered first in patients with minimal to mild bladder wall thickening since some degree of bladder wall hypertrophy can result from dysfunctional elimination. However, the degree of bladder wall thickening in this patient is greater than one would expect from dysfunctional elimination alone.

Answer 11

3 The course of adult polycystic disease is often complicated by flank pain, hematuria, nephrolithiasis and urinary tract infections. Infected cysts are a major problem because they are difficult to treat and may progress to intrarenal and perinephric abscesses. Fifty to 75% of patients with polycystic disease, mainly females, are said to develop UTIs during the course of their illness. Renal cysts do not communicate with the collecting system; therefore urine cultures may be negative. If the patient is generally well, antimicrobial therapy is the best first step. However, it may be ineffective because of choice of antibiotic which have poor penetration in the diseased kidneys. Most antibiotics, including aminoglycosides, penicillins, cephalosporins and macrolides penetrate polycystic renal cysts poorly. Drugs that penetrate cysts reasonably well include chloramphenicol, trimethoprim-sulfamethoxazole, clindamycin and ciprofloxacin. In this particular case where the patient is not toxic, oral treatment with ciprofloxacin and close observation is warranted. If the patient does not respond and/or her fever persists while on ciprofloxacin, percutaneous aspiration or drainage of the cyst would be indicated.

Answer 12

4 The Southwest Oncology Group (SWOG) trial 8794 demonstrated that adjuvant radiation reduces the risk of biochemical treatment failure by 50% over radical prostatectomy alone. Four hundred thirty-one subjects with pathologically advanced prostate cancer (extraprostatic extension, positive surgical margins, or seminal vesicle invasion) were randomly assigned to postoperative radiotherapy or observation. Three hundred seventy-four eligible patients had a median follow-up of 10.2 years. For patients with a postsurgical PSA of 0.2 ng/mL, radiation was associated with reductions in the 10-year risk of biochemical treatment failure (72% to 42%), local failures (20% to 7%), and distant failures (12% to 4%). Moreover, radiation to the prostate bed reduced the risk of metastatic disease and biochemical failure at all postsurgical PSA levels. It is advisable to wait at least 3-4 months after surgery to allow complete wound healing and return of urinary continence. If salvage radiotherapy is planned, it should be initiated before the PSA level rises much above 0.5 ng/ml. Although some patients with PSA recurrence are better managed with hormone therapy for PSA relapse, the long-term side effects would make adjuvant radiation the best choice particularly at this early post-operative stage.

Answer 13

1 Androgen replacement in hypogonadal men does increase sexual activity and interest. The relationship between androgen replacement and penile erection is not straightforward. When evaluated with nocturnal penile tumescence testing, hypogonadal men demonstrate decreased erectile activity and this abnormality is corrected with testosterone replacement. Laboratory tested erectile responses to erotic films, however, are usually normal in hypogonadal men. These observations are consistent with the conclusion that the major effect of testosterone therapy on sexual function is to enhance libido and not to directly improve penile erection in a sexual setting. None of the other drugs are known to exert these effects.

Answer 14

5 Most major bleeding from the pelvis following blunt trauma can be controlled by packing the pelvis and planned re-exploration and/or angiography with embolization in the radiographic suite. Ligation of hypogastric arteries or veins is seldom helpful in management because bleeding occurs from multiple pelvic veins. On-table arteriography is technically difficult, time consuming, and provides poor images and should therefore not be used. The use of a MAST suit in such cases has not been proven to be effective. Bleeding is due to trauma and unlikely to respond to medical therapy.

Answer 15

1 An increasing amount of data has accumulated to suggest that a 2 cm margin may not be necessary in all patients undergoing penile cancer resection. Two specific studies have challenged this surgical issue. In a prospective histologic analysis of 64 penectomy specimens, Agrawal and associates concluded that tumor grade highly correlated with microscopic tumor spread. The maximum proximal histologic extent was 5 mm for grade 1 and grade 2 tumors and 10 mm for grade 3 tumors. After performing a retrospective pathologic review of 12 penectomy specimens, Hoffman and colleagues also found seven patients with disease of pathologic stage T1 or greater with microscopic margins measuring less than 10 mm. None of these patients had disease recurrence at a mean follow-up of 32.4 months. The most important factor in determining risk of residual disease in patients with less than a 2 cm margin is tumor grade. This patient is therefore at low risk of recurrence and should be monitored accordingly.

Answer 16

1 There is considerable postoperative edema at the level of the bladder four to six weeks following a tapered ureteroneocystostomy. In addition, high grade VUR results in diminished compliance of the ureter and renal pelvis. Prior to surgery, it is common to see a normal upper tract on renal ultrasound or only minimal hydroureteronephrosis. After surgery the combination of the resistance from the ureteral tunnel and operative edema can unmask the poor compliance of the ureter and kidney resulting in the appearance of significant hydroureteronephrosis. This should not be interpreted as obstruction. When evaluating the immediate post operative ultrasound it is necessary to put it into perspective with the initial degree of ureteral and renal dilation noted on the VCUG and not directly compare it to the preoperative renal ultrasound. In general, there is no major concern for obstruction if the degree of hydronephrosis on the post operative ultrasound correlates with the degree of dilation of the collecting system seen on the preoperative VCUG. Increased dilation due to edema and a poorly compliant system will begin to improve after six weeks. If this dilation persists after several months, a MAG 3 renal scan should be performed to aid in determining if post operative obstruction exists. All of the other options would be too premature at this point in time.

Answer 17

1 Cystine stone formation is the only type of metabolic stone disease which can be determined specifically based on the urinary concentration of a specific ionic constituent. In most patients, once the urinary concentration of cystine increases to more than 200 mg of cystine per liter of urine, cystine crystals will precipitate out of solution with subsequent formation of cystine calculi. If one can reduce the cystine concentration below 200 mg per liter, either with increased urinary volume or reductions in cystine excretion, cystine stone disease can be prevented. However, a high percentage of patients with cystine stone disease will also have concurrent metabolic abnormalities and appropriate metabolic evaluation with subsequent treatment should also be instituted.

Answer 18

2 The association between testicular tumors/nodules and CAH has been recognized for many years and are defined as testicular adrenal rest tumors (TART). Tumors are considered to be aberrant adrenal tissue that has descended with the testes and has become hyperplastic due to ACTH stimulation. The recommended treatment of TART consists of increasing the glucocorticoid dose to suppress ACTH secretions. Biopsy and or removal is not indicated unless increasing medical therapy fails. Antibiotics and abdominal pelvic CT scan are not indicated.

Answer 19

5 The majority of arterial ureteral fistulas occur in patients who have had extensive pelvic surgery, XRT, and indwelling ureteral stents. Most fistulas involve the common iliac artery but they can also occur in the hypogastric artery. Patients can experience high volume bleeding resulting in hemodynamic instability. Emergency arteriography should be performed if this complication is suspected. While embolization of the common iliac artery will control hemorrhage, a femoral to femoral artery bypass is required to provide adequate circulation to the ipsilateral lower extremity. Placement of an endovascular stented graft or an autologous vein covered stent are less invasive options obviating the need for vascular reconstructive surgery in a patient with limited life expectancy and are the preferred treatment method. The ureteral stent should be removed and a percutaneous nephrostomy placed after this procedure to limit recurrent fistula formation.

Answer 20

4 A split thickness skin graft takes much more readily than a full thickness skin graft or a dermal graft because capillary ingrowth into the graft is more rapid. Skin flaps and musculocutaneous flaps have no role in the acute management of avulsion injuries.

Answer 21

1 The flap valve or Mitrofanoff principle gives excellent continence with ease of catheterization in most cases. When the appendix is not available, reconfigured ileum (Monti) is preferred because it gives a uniform tube with a small mesentery in the center that facilitates tunneling into the bladder and creation of an abdominal stoma. Tapered ileum leaves a bulky mesentery along the length of the channel and the mucosal folds are oriented transversely potentially making catheterization difficult. An ileal conduit is not ideal long-term management in children because of long-term upper tract deterioration. An incontinent ileovesicostomy requires an appliance has been documented to be problematic in obese patients. The bladder is likely thickened and small; the chance of a detrusor flap reaching the abdominal wall without being complicated by stomal stenosis is small. Intussuscepted ileum historically has a high failure rate with regards to stomal incontinence.

Answer 22

4 In the setting of an ileal conduit urinary diversion, ammonium absorption occurs with chloride in exchange for hydrogen and bicarbonate ions, and may be accompanied by renal potassium wasting. This results in a hypokalemic hyperchloremic metabolic acidosis. Hyponatremic hypochloremic hyperkalemic metabolic acidosis occurs with the use of jejunum due to sodium chloride loss with increased reabsorption of potassium and hydrogen ions. Use of stomach may lead to hypochloremic hypokalemic metabolic alkalosis due to hydrogen and chloride loss with renal oversecretion of potassium to compensate for proton loss.

Answer 23

3 Although ureteral peristalsis does increase, and the ureters do dilate during pregnancy, neither of these physiologic changes are associated with decreased stone formation. During the third trimester of pregnancy, urinary citrate levels are known to increase dramatically. Urinary citrate is a potent inhibitor of calcium oxalate crystallization, and should help protect against stone formation. Neither hypocalciuria nor hypouricosuria are routinely associated with pregnancy.

Answer 24

5 The critical step in patients undergoing upper pole, partial nephrectomy, to remove a non functional segment, is dissecting the abnormal ureter from the renal hilum so as not to cause vascular injury to the normal lower pole. The adrenal gland should be left in situ and not disturbed. The distal ureter especially in a male is rarely an issue if not completely removed. The lower pole of the kidney can be mobilized for exposure but is not typically necessary. Reduction of the renal pelvis is not an issue.

Answer 25

1 Patients who have undergone an abdominoperineal resection are at risk for developing denervation of not only their bladder but also the urethral sphincter mechanisms. Denervation of the smooth muscle in the area of the bladder neck and membranous urethra places these patients at considerable risk for incontinence following transurethral resection of the prostate. Because of the possibility of urinary incontinence following TURP or TUIP, the preferred management of this patient is continued CIC. Bethanechol is not clinically effective in the doses that can be administered orally. Tamsulosin will not be effective in the absence of effective detrusor contractions.

Answer 26

2 The CT is consistent with an infected urachal cyst. Broad spectrum antibiotics without a culture is not prudent. This is not a tumor, therefore biopsy is unnecessary. Excision is definitive therapy but is most appropriate after drainage and treatment of an abscess. Endoscopy may reveal some inflammation at the dome of the bladder but will not be therapeutic or diagnostic.

Answer 27

4 Two major problems are found to exist with cecal or colon stomas 1) stomal stenosis will develop in up to 30% of patients; this can be managed with either stomal revision or placement of a cecostomy tube through the stenotic channel. 2) washout failure, defined as failure to pass little or any of the enema from the rectum within one to two hours following instillation of irrigation fluid. Approximately 5-10% of patients with washout failure will need a diverting colostomy. The maximum amount of tap water that can be used for ACE irrigations before alterations in serum sodium will occur can be calculated by the formula of body weight (kg) x 0.035 L/kg for example in this 30 kg child. 30 kg x 0.035 liters/kg = 1.05 liters maximum volume. The physician may use water volumes higher than what is calculated but the risk of hyponatremia rises with higher volumes, the onset of hyponatremia and the risk of water intoxication will of course be dependent upon the type of fluid instilled and dwell time within the bowel. If water volumes greater than calculations are used the patients serum electrolytes should be checked at monthly intervals until they can be documented to be stable, after that time electrolytes can be checked with routine follow-up. Alternatives to significantly increasing the volume of calculated instilled fluid involve changing irrigant fluid to polyethylene glycol irrigations, long term use of this substance is however associated with the intermittent development of C. difficile colitis. Magnesium citrate or phosphate enemas may be instilled in the ACE prior to washout to decrease irrigant volume however these maneuvers have been associated with resultant hypermagnesemia, hyperphosphatemia and hypocalcemia. In patients with washout failure following high volume irrigations of a right colonic ACE altering the stomal site/colonic tube to the left colon has been documented to reduce the volume of irrigant; result in successful fecal continence and save the majority of these patients from the need for a diverting colostomy.

Answer 28

4 During the massive urinary sodium losses occurring during the diuresis phase of acute tubular necrosis, potassium is also lost resulting in life-threatening hypokalemia. During diuresis the Na2kB pump is overwhelmed and exchange fails to occur

Answer 29

1 The fragility of stones determines their ability to be fractured with therapies such as SWL. The fragility of a stone will affect the outcome of therapy. Calcium oxalate monohydrate, brushite and cystine stones have been shown to be the least fragile and are less likely to respond to therapy with SWL.

Answer 30

5 Observation is a reasonable choice in young couples with infertility of less than one year's duration. However, the finding of round headed sperm is consistent with absence of the acrosome and individuals with this finding are sterile. Standard intrauterine inseminations and in vitro fertilization are unsuccessful because the sperm cannot fertilize an egg without a normal acrosome. Varicocele repair will not improve the morphology. The only method that will induce a pregnancy using the patient's sperm is in vitro fertilization using intracytoplasmic sperm injection (ICSI). Even regular ICSI has resulted in low pregnancy rates. Current approaches combine assisted oocyte activation with ICSI. The alternative is donor insemination.

Answer 31

3 Incidentally discovered small asymptomatic renal tumors do not mandate a waiting period prior to transplantation. Repeating the CT scan with contrast risks further nephrotoxic injury with preexisting borderline renal function, and will not change the management of the renal mass. Although partial nephrectomy may carry the advantage of preserving additional renal mass, this is not applicable to this patient. The appropriate management in this setting is simultaneous nephrectomy and transplantation.

Answer 32

3 This child likely has a delayed bleed from a renal laceration. The CT demonstrates devitalized areas of the kidney with a collection of blood and urine. This is best managed by embolization after confirmation by arteriogram. Open surgery will more likely result in nephrectomy or heminephrectomy. Percutaneous nephrostomy or retrograde ureterogram will not treat the continued bleeding. A retrograde study would be indicated if one were suspecting a pelvic tear or a UPJ disruption because of medial extravasation.

Answer 33

5 The patient has tumor lysis syndrome and early acute oliguric renal failure secondary to uric acid nephropathy. The normal ultrasound without hydronephrosis rules out obstruction as the cause of the renal failure. Initial management is hydration, urinary alkalinization followed by reduction of uric acid with allopurinol. If that fails, hemodialysis may be necessary. Isotope renogram is not indicated. Renal biopsy, to rule out interstitial tumor infiltration, is also not indicated since the circumstance strongly suggests tumor lysis issues. The patient has no ureteral obstruction and, thus, cystoscopy and retrograde pyelogram with stent placement would not be helpful.

Answer 34

2 Considerations for apparent early graft dysfunction include infection, renal allograft rejection, urinary or vascular obstruction, cyclosporine or tacrolimus nephrotoxicity, hyperglycemia, and dehydration. A screening work-up consisting of physical exam followed by basic laboratory tests and ultrasound are appropriate. In this case, the prominent physical exam finding of tremor suggests tacrolimus toxicity that can be further evaluated by determining the serum level of the immunosuppressant tacrolimus (calcineurin inhibitor). Mycophenolate mofetil is an antibiotic with immunosuppressive qualities. It is clinically indicated for cardiac and renal transplantation and the treatment of psoriasis and rheumatoid arthritis. Side effects of mycophenolate mofetil include anemia, leukopenia, thrombocytosis, GI bleeding, sepsis, lymphoma, skin cancer, and pulmonary fibrosis. It is not associated with a decrease in renal function. However, its use may result in elevation of tacrolimus and cyclosporin blood levels. The latter may interfere with renal graft function.

Answer 35

1 This patient has adrenal insufficiency secondary to bilateral adrenal hemorrhage. This can occur in anticoagulated patients, typically during the first three weeks of therapy. The initial therapy should be administration of I.V. fluids and glucocorticoid therapy. Fresh frozen plasma is not acutely indicated with an adequate hemoglobin level. Kayexalate will help lower a high potassium but not the hypotension from adrenal steroid deficiency. Chronic but not acute adrenal insufficiency is treated with fluorohydrocortisone. Vitamin K will help restore clotting factors depleted by warfarin therapy but is not the initial therapy for this patient.

Answer 36

2 Quadrivalent Human Papillomavirus vaccine immunizes against types 6, 11, 16 and 18. Types 16 and 18 are associated with 70% of cervical cancer cases. Types 6, 11, 16, and 18 are associated with 90% of cases of genital warts. The vaccine has only been tested in females and is indicated in females age 9-26 for the prevention of cervical cancer, precancerous lesions and genital warts caused by these subtypes. There has been no testing of vaccine efficacy in males.

Answer 37

5 All patients with an output greater than 200 ml/hr have postobstructive diuresis and should be monitored. High risk patients with chronic obstruction, edema, congestive heart failure, HTN, weight gain and azotemia are most likely to exhibit a postobstructive diuresis after the release of obstruction. In the high risk patient a spot check urine for osmolality, sodium and potassium will allow for the determination of the type of postobstructive diuresis and will guide in further management. High risk patients should have vital signs, including postural blood pressure and output measured hourly. D5 1/2 NS is an appropriate replacement fluid in the patient with an elevated BUN and creatinine but generally replacement is given at half of the previous hours urine output.

Answer 38

2 Renin-mediated HTN sometimes occurs in acute unilateral renal obstruction and may present a clinical picture suggestive of a renovascular etiology; however, angiographic studies do not show a vascular lesion. A transient hyperreninemia initiates the HTN and the HTN is probably sustained by complex volume-vasoconstricting abnormalities that are dependent on the duration of the obstruction and the presence of a contralateral normal kidney. The abnormalities are corrected by relieving the obstruction and the blood pressure in turn reverts to normal. This type of HTN usually does not occur in a solitary hydronephrotic kidney or bilateral hydronephrosis because of compromised renal function with lowering of renin levels due to impairment of overall sodium and water excretion.

Answer 39

2 This patient has steinstrasse and appears to be septic, thus, his upper tract should be drained. Placement of a percutaneous nephrostomy tube is an option that will accomplish this. The fragments will pass spontaneously with a nephrostomy tube in place in upwards of 70% of cases, and thereby avoid ureteroscopic extraction or SWL of the ureteral fragments. Medical expulsive therapy will probably not be effective in this case.

Answer 40

2 This patient's presentation is lacking in the usual signs and symptoms of gonorrhea, but an oxidase positive culture on Thayer-Martin medium is diagnostic of Neisseria gonorrhea. Thayer-Martin media contain various antibiotics (vancomycin, colistin and nystatin) and specific growth-promoting agents with hemoglobin (sheep's blood) that inhibits or totally suppresses the growth of accompanying bacterial flora while allowing pathogenic Neisseria species to grow normally. Diagnosis of primary syphilis is by darkfield microscopy and direct fluorescence antibody (DFA) test of specimens obtained from the lesion. Alternatively, nontreponemal serologic testing with rapid plasma reagin (RPR) or Venereal Disease Research Laboratory (VDRL) can be used to diagnosis primary syphilis. Chancroid is caused by Haemophilus ducreyi and this organism is fastidious and difficult to culture. Diagnosis is usually made by gram stain showing gram negative streptobacilli. Lymphogranuloma venereum (LGV) is caused by Chlamydia trachomatis types L1, L2 and L3. The diagnosis of LGV is primarily clinical as cultures are positive only 30-50% of the time from the cutaneous lesions: and accessory glandular infection may be the only manifestations of active gonorrhea. Kaposi's sarcoma is caused by HIV.

Answer 41

4 The risk of hepatitis B virus (HBV) developing into clinical infection after a needlestick exposure to hepatitis B surface antigen positive blood ranges from 7% to 30%. Between 5% and 10% of persons with acute HBV infection become chronic carriers; 15% to 25% of carriers will eventually die of liver cancer or cirrhosis. The risk of HIV infection after a needlestick exposure to HIV-infected blood is, on the average, approximately 0.4%. Thus, the death rate may be slightly higher with hepatitis exposure, and the morbidity rate is far higher.

Answer 42

2 Exogenous testosterone will suppress pituitary production of LH and FSH. Prolactin levels will be unaffected. Semen volume, which is dependent on circulating testosterone levels, should be unchanged or increased. However, intratesticular levels of testosterone will decrease, resulting in lower sperm production and decreased sperm concentration.

Answer 43

4 The clinical picture is consistent with cauda equina syndrome, which is associated with disc disease (severe central posterior disc protrusion) and other spinal canal pathologies that involve the L4-S2 region. Additional features of the presentation include loss of voluntary control of both anal and urethral sphincters and of sexual responsiveness. The most consistent urodynamic finding is that of a normally compliant areflexic bladder with either normal innervation or incomplete denervation of the perineal floor musculature. Disc protrusions of the lumbar spine interfere with the parasympathetic and somatic innervation of the lower urinary tract, striated sphincter and other pelvic floor musculature, and afferent activity from the bladder and affected somatic segments to the spinal cord.

Answer 44

5 Nongonococcal urethritis caused by Chlamydia trachomatis or Ureaplasma urealyticum cannot be distinguished clinically, but either tetracycline or azithromycin is usually effective against both. Sexual partners should also be treated. If the signs and symptoms of urethritis do not improve with a tetracycline, infection with tetracycline-resistant U. urealyticum may be present; this usually responds to an azithromycin. Relapse may be due to reinfection by an untreated sexual partner, and the patient and all partners should be retreated. When C. trachomatis causes mucopurulent cervicitis, it usually responds to the same regimen of tetracycline or azithromycin used to treat urethritis.

Answer 45

1 Percutaneous or surgical revascularization of the internal pudendal arteries is not indicated owing to the patient's age and associated atherosclerotic vascular disease secondary to smoking. There is no indication for venous ligation. Owing to the vascular disease, penile injections may not be successful but should be implemented prior to insertion of a penile prosthesis.

Answer 46

5 The description suggests an impending supersonic transport (SST) deformity which is a ventral chordee of the glans whereby the distal aspects of the cylinders inadequately extend distally under the glans creating a floppy appearance. The floppy appearance mimics the drooped nose of the Concorde, a supersonic transport. A likely basis for the problem is inadequate dilatation and sizing of the corporal spaces. If this is identified during prosthesis placement, the corporotomies should be reopened and the corporal bodies inspected to be sure proximal perforation has not occurred. Redilation and remeasurement of corporal bodies are then performed, and the same cylinders can usually be reinserted adding rear-tip extenders to achieve appropriate length. A distal corporal plication (Ball procedure) is not generally required during initial prosthesis placement. The device should remain in the deflated position at the completion of surgery until the time of device activation and initiation of use to avoid the risks of an unexpanded cavity space for the reservoir (that is associated with autoinflation), penile pain and distal corporal perforation.

Answer 47

3 A deficiency of 20,22-desmolase, 3B-hydroxysteroid dehydrogenase and 17-hydroxylase enzymes occur with congenital adrenal hyperplasia but rarely cause genital ambiguity in a 46 XX female. 17B-hydroxysteroid dehydrogenase is primarily a testicular enzyme. A 21-hydroxylase deficiency will cause CAH in both sexes but in a 46 XX individual with ovaries it will lead to genital ambiguity. Only enzyme defects beyond the 17-hydroxyprogestone stage of steroid biosynthesis will produce excessive androgenic substances.

Answer 48

2 The patient's findings are classic for chancroid which is due to H. ducreyi. This is the most common sexually transmitted disease worldwide. It affects men three times more than women. It is associated with inguinal adenopathy that is typically unilateral and tender with tendency to become suppurative and fistulize. Single-dose treatment with azithromycin 1 gm orally or ceftriaxone 250 mg intramuscularly is first line therapy. While ciprofloxacin can be a secondary regimen, resistance to ciprofloxacin has been reported in some regions. Patients should be reexamined in five to seven days. Sexual partners should be treated if sexual relations were held within two weeks before or during the eruption of the ulcer.

Answer 49

1 This patient has mixed urinary incontinence. Although a sling or periurethral injectable agent may resolve the stress incontinence demonstrated on physical examination, this is not her primary complaint. A pessary is not indicated since she has no prolapse symptoms and it is not likely to cure her mixed symptoms. Several studies have found that urge predominant mixed urinary incontinence symptoms often respond to antimuscarinics medication.

Answer 50

2 Properties of uropathogens, sexual activity, feminine hygiene practices and the use of an IUD and/or spermicide may increase the frequency of UTIs in predisposed women, however they are not the most important etiologic factors. Many women have uropathogenic bacteria present in their bowel, use various contraceptive and hygiene methods, and are sexually active without developing infections. E. coli must colonize the peri-urethral area before an uncomplicated infection can occur. Coliform organisms are recovered only rarely from the region of the vaginal vestibule and external urethra in otherwise healthy women who do not have recurrent UTIs. It is postulated by most researchers that host factors rather than specific pathogenicity of the micro-organisms are the prime determinants of colonization. E. coli tend to adhere more to vaginal and buccal epithelial cells obtained from women with recurrent infection than to controls. This explains why certain women are prone to frequent recurrent infections. It would also explain why women with asymptomatic bacteruria are more prone to recurrent infection with marriage and pregnancy and would account for UTIs associated with intercourse, various contraceptive methods, etc., in highly susceptible women.

Answer 51

2 Disruption of the ureteropelvic junction in a child secondary to trauma is a prime indicator for operative intervention. His kidney should be salvaged and a percutaneous nephrostomy tube may not be diverting. While the distal blood supply of the ureter has been disrupted due to his previous surgery, his ureter should still have an adequate blood supply from the middle ureteral vessels. A primary repair is the best treatment option. Transureteroureterostomy would potentially put the contralateral renal unit at risk unnecessarily and not likely to be technically feasible.

Answer 52

5 Nonoperative management is a viable option in selected patients with vesicoenteric fistulas, however, patients chosen for such treatment should be minimally symptomatic with benign fistulas. For those requiring surgical exploration, both one and two stage procedures have been based on clinical circumstances. The decision regarding a one or two stage procedure is influenced by the location and etiology of the fistula, the patient's general condition, the timing of the exploration relative to the original procedure, the presence of pelvic abscess, the presence of colonic obstruction, and the severity of the inflammatory response. Patients without gross fecal contamination can be treated with a one-stage procedure, whereas those with unprepped bowel, gross fecal contamination, severe inflammatory response, or abscess require a two-stage procedure.

Answer 53

5 Parathyroid hormone mediates renal reabsorption of calcium in the distal nephron. More proximally in the nephron, calcium is reabsorbed in concert with sodium. Vitamin D influences calcium homeostasis primarily by enhancing small bowel absorption. Significant hypocalcemia stimulates renal calcium preservation by inducing parathyroid hormone secretion. Aldosterone mediates distal renal preservation of sodium in exchange for available hydrogen and/or potassium, and has no direct effect on calcium reabsorption.

Answer 54

4 Reflux in newborn boys is commonly high grade and associated with uninhibited detrusor contractions during filling, high pressure voiding due to elevated outlet resistence, detrusor-sphincter dyssynergy, and high postvoid residuals. Uninhibited, detrusor contractions associated with coordinated voiding is normal in infants and not associated with high grade VUR. Compliance and contractility are generally within the range of normal for these boys. The best treatment for infant boys with high grade VUR is prophylactic antibiotics and observation. Most of these infants will decrease their outlet resistance and resolve their VUR with neurourologic maturation during the first year of life.

Answer 55

3 This patient will likely have worsening stress urinary incontinence postoperatively. A concomitant pubovaginal fascial sling would treat the stress incontinence and have no increased risk of infection or urethral erosion. Concomitant placement of a synthetic sling should be avoided because of the potential risk of infection and erosion into the urinary tract. A Martius fat pad will not treat the incontinence. Collagen is unlikely to provide long term relief of stress urinary incontinence. It is unnecessary to perform a retropubic exploration at the time of a vaginal incision for urethral diverticulectomy, in addition, the intrinsic sphincter deficiency as suggested by the open bladder neck is treated better with a sling than a Burch procedure.

Answer 56

4 The CT findings are consistent with a metastatic lesion and percutaneous biopsy is indicated to confirm this diagnosis. If an adrenal mass has an attenuation of less than 0 Hounsfield units (HU), it is considered an adenoma. If the attenuation value is between 0 and 20 HU, chemical shift MRI is recommended. If lipid is detected in the lesion with this test, the mass is most likely an adenoma. Percutaneous biopsy is indicated when the attenuation is greater than 20 HU or if the lesion is otherwise indeterminant. To proceed immediately to an adrenalectomy in this setting of a previous primary malignancy such as lung cancer is inappropriate until tissue diagnosis is obtained. Treatment options will depend upon pathology of the lesion.

Answer 57

5 Currently one third of the symptomatic patients undergoing detethering of the spinal cord will present with urologic complaints, 50% will present with the late findings of lower limb weakness/gait disturbance and approximately 15% with back pain. Bowel dysfunction is a rare presenting complaint. Damage from a tethered cord is the result of inadequate oxygen metabolism in the spinal cord. The cord becomes tethered between the site of tethering and where the anterior and posterior nerve roots exit the canal. Repetitive flexion and extension and/or Valsalva activity of any type kinks the arterioles and venules, thereby reducing blood supply to the tethered cord. The clinical findings of tethered cord come from accumulative hypoxemic damage and may occur at any age. The diverse structure of the spinal cord plays a large role in the pathogenesis of this disorder; specifically interneuronal axon connections have the highest oxygen requirements and are the first to become damaged. Clinically, this means the pelvic nerves and the sacral reflex arc will be the first to manifest the hypoxic damage, lower limb weakness and back pain occurring at a later time. Once an MRI scan depicts a tethered or abnormally lying cord, surgical detethering will not correct the MRI picture. Long-term follow up has revealed that up to 20% of tethered cords may redevelop symptomatic findings of re-tethering. The inability of the MRI scan to rule out re-tethering places the urologist and urodynamic testing in a key position. Specifically serial urodynamic tests or electromyography of the muscles involved with the sacral reflex arc are monitored at set intervals usually three months post surgical release of the cord and then again at six to twelve month intervals. Alterations in the urodynamic tests will result in increase attentiveness by the neurosurgeon for the development of re-tethering of the spinal cord.

Answer 58

5 Urodynamic testing is reasonable in patients who have failed prior operative treatment. In patients who have obstruction and detrusor overactivity relief of the obstruction will generally result in resolution of the detrusor overactivity. Although antimuscarinics may help the patient's symptoms they do not treat the underlying persistent obstruction - clearly present in this case. 5-alpha-reductase inhibitors reduce prostate volumes and modestly improve symptoms but may not treat the underlying obstruction. CIC or neuromodulation will not address the obstruction. TURP is most likely to resolve the obstruction and improve symptoms.

Answer 59

3 Non-refluxing ureterointestinal anastomoses do not prevent upper tract colonization. Virtually all upper tract systems are found to be colonized when urine is aspirated above the non-refluxing anastomoses. Studies which have compared non-refluxing colon conduits to refluxing ileal conduits show similar rates of upper tract deterioration. While a properly functioning non-refluxing ureteral anastomosis does prevent pressure transmission to the upper urinary tract, this benefit is in part offset by a higher incidence of ureterointestinal stricture. This has caused some to question the benefit of creating non-refluxing anastomoses in any form of urinary diversion whether conduit or continent. There is no impact on metabolic issues or stone formation.

Answer 60

1 This patient has symptoms characteristic of hypovolemic hypernatremia. This has occurred due to water loss from his diabetes insipidus without the ability to replace water or electrolytes orally. It is essential to first restore plasma volume with a relatively isotonic solution like lactated Ringers. The hypernatremia should then be corrected slowly with increased free water being given. Correction should decrease serum levels by no more than 10 mEq per day to prevent intracranial swelling and fatal complications. Hypertonic saline is contraindicated.

Answer 61

4 Proximal urethrovaginal fistulae may present with constant dribbling incontinence. A large (5 mm) urethrovaginal fistula is unlikely to close with urinary drainage or fulguration. The safety of synthetic materials is not established in the setting of urinary fistula or prior urethral diverticulectomy. Surgical repair of the fistula should be undertaken two to three months post-operatively, and re-evaluation of the SUI done once the fistula is repaired. Long term indwelling urethral catheter is not recommended due to the development of chronic bacteruria and chronic inflammation.

Answer 62

4 Major vascular injury is a rare but serious complication that occurs in 0.11-2% of cases. The right common iliac artery lies close to the mid-line at the inferior umbilicus. Therefore, with placement of an umbilical trocar, the right common iliac artery is the most commonly injured vessel, followed by the aorta. In contrast, the IVC is less frequently involved because of its lateral location in relation to the aorta. The common iliac veins are rarely involved given their posterior location in relation to the common iliac arteries.

Answer 63

3 Ureteral obstruction is a recognized complication of reconstructive vascular procedures. The incidence of temporary, asymptomatic hydronephrosis is 12-30%, and mild or moderate permanent ureteral obstruction is seen in 2-14% of patients. Most patients develop ureteral obstruction within one year following the procedure; however, delays up to 14 years have been reported. Retroperitoneal fibrosis secondary to the surgical procedure is the most common cause of ureteral obstruction and is believed to be secondary to bleeding or excessive periureteral dissection. The other choices are all causes of obstruction, but not the most common.

Answer 64

5 Among the parameters mentioned, only the presence of a positive UA would preclude treatment with botulinum toxin. Patients of all ages have been treated with botulinum toxin and certainly patients with neurological conditions such as multiple sclerosis have been effectively and safely treated. Though no concrete data exist to define at what point it is reasonable to inject detrusor botulinum toxin after injection at other sites, most studies have suggested that at least three months pass between injections. The presence of Hirschsprung's disease is not a known contraindication to botulinum toxin bladder injections. A contraindication to botulinum toxin injection is the presence of an active urinary tract infection.

Answer 65

4 Ultrasonography is a very useful imaging modality for distinguishing kidney masses. Specifically, it is able to use the acoustic properties of the renal parenchyma to aid in diagnosis. The presence of an echogenic mass immediately eliminates the diagnosis of simple cyst, as these are usually echo-free. In addition, while lobar nephronia may appear like a mass on ultrasound, it is usually echo-poor or echo-free as well. RCCs, intrarenal abscesses and angiomyolipoma all may be echogenic. Angiomyolipomas are usually echogenic, while RCCs and intrarenal abscesses have variable echogenicity. The key here is the speed-propagation artifact, which is due to the presence of fat in the tumor. In this case, the speed of sound in the fat is significantly slower than that in the soft tissue, which causes the unique artifact that confirms the diagnosis of angiomyolipoma.

Answer 66

5 The first branch of the left renal artery is a small ureteral branch, but the first major branch is the posterior or dorsal artery. This artery primarily supplies the posterior segment of the kidney alone, but occasionally may provide a small branch to the apical segment as well. The anterior or ventral artery generally supplies branches to all but the posterior segment.

Answer 67

5 Re-vascularization is typically recommended in renal artery stenosis when \> 75% occlusions occur either bilaterally or in a solitary single kidney. With severe renal loss (serum creatinine \> 4 mg/dl), the likelihood of renal recovery is substantially reduced and revascularization is not recommended. Atherosclerotic renal vascular HTN should be treated medically, typically with at least three medications before resorting to revascularization. Medial fibroplasia typically is not progressive and revascularization for this process is rare.

Answer 68

5 Hypokalemia, an elevated serum aldosterone level and a normal peripheral renin level suggest primary hyperaldosteronism. The CT shows no adrenal mass suggesting adrenal hyperplasia. An MRI with T2 weighted images is useful in cases of a pheochromocytoma but this is not suggested by the biochemical data. An MIBG scan lacks sensitivity. Venous localization studies are most useful in this case. Venous localization studies demonstrate convincingly the pathology is from the left adrenal, suggesting unilateral hyperplasia. Spironolactone would be the first treatment. If the HTN and hyperkalemia are not corrected, a left adrenalectomy would be indicated.

Answer 69

3 The main arterial supply of the sigmoid colon is from the sigmoid and superior hemorrhoidal branches of the inferior mesenteric artery (IMA). The major collateral vessels are the middle and inferior hemorrhoidal arteries which arise from the internal iliac artery. They anastomose freely with the superior hemorrhoidal branches. It is distributed to the rectum, anastomosing with the inferior vesical artery, superior rectal artery, and inferior rectal artery. The right colic artery arises from the superior mesenteric artery and does not have collaterals to the distal colon. The superior hemorrhoidal arteries and sigmoid arteries are continuations of the IMA and is filled retrograde when the IMA is ligated. The middle sacral artery arises from the back of the aorta and gives some blood supply to the rectum.

Answer 70

4 While tamsulosin had been the most widely publicized alpha-1a blocker to be associated with intra-operative floppy iris syndrome (IFIS) during cataract surgery, other alpha-blockers have as well (including super-selective and less selective agents). Although not eliminating the risk of IFIS, discontinuing these medications one to two weeks prior to surgery lowers the incidence

Answer 71

5 Excess circulating glucocorticoids may be due to adrenal adenoma or carcinoma, or to ectopic secretion of ACTH or CRH. This patient has no evidence of Cushing's disease or ACTH dependent disease. She most likely has a contralateral adrenal source and glucocorticoid suppression with metyrapone is the most appropriate next step. Agents include aminoglutethimide, which blocks the conversion of cholesterol to pregnenolone; metyrapone, which blocks the conversion of 11-desoxycortisol to cortisone. Patients given aminoglutethimide are prone to develop adrenocortical insufficiency because aldosterone production is also impaired. Metyrapone does not normally result in salt wasting because of increased production of desoxycorticosterone, a potent mineralocorticoid. A right adrenalectomy in a patient with a solitary adrenal gland would commit the patient to lifelong steroid replacement.

Answer 72

5 In patients with prostatic rhabdomyosarcoma who have failed chemotherapy and XRT, the best form of diversion, with the lowest complication rate is a transverse colon conduit. Once the patient has completed additional chemotherapy and no recurrence of malignancy has occurred for a minimum of two years, conversion to a continent urinary diversion can be considered.

Answer 73

3 This patient has dangerously elevated intravesical pressures and a continuously draining ileovesicostomy will permit low pressure bladder emptying. An indwelling catheter has the risk of UTI, stones, cancer and urethral erosion. The incompetent outlet of the ileovesicostomy acts as a "pop off" as the bladder fills and therefore the intravesical pressure will remain safe. Bladder neck fascial sling is not necessary as it is unlikely that this individual will have stress incontinence per urethra given her high abdominal LPP and her limited mobility. She is a quadriplegic and catheterization following augmentation cystoplasty through an abdominal stoma or her urethra increases her risks, dependence on a caretaker, and is not practical.

Answer 74

1 Collecting duct carcinoma is an unusual and aggressive type of renal tumor. While this patient is at risk for disease recurrence and progression, she is at this time without evidence of disease and no further therapy is indicated. There are no data that demonstrate efficacy of any form of adjuvant therapy.

Answer 75

4 The treatment of hyperchloremic metabolic acidosis requires administration of alkalinizing agents or blockers of chloride transport. In patients in whom excessive sodium loads are undesirable, nicotinic acid or chlorpromazine may be administered to control the acidosis. Nicotinic acid and chlorpromazine inhibit cyclic AMP and thereby impede chloride transport. Furosemide will not correct the metabolic acidosis. Bicitra, sodium bicarbonate, and Polycitra all contain significant amounts of sodium which could potentiate the congestive heart failure.

Answer 76

1 The prevention of DVT in patients undergoing anti-incontinence and pelvic reconstructive surgeries should be dictated by preoperative individual patient and procedure specific DVT risk factors. In an uncomplicated patient without risk factors for DVT undergoing an anti-incontinence procedure for the treatment of stress urinary incontinence, early postoperative ambulation is considered adequate prophylaxis against postoperative DVT.

Answer 77

1 Toxic metabolic effects secondary to drug reabsorption of methotrexate from intestinal mucosa used in urinary tract reconstruction can occur. Vigorous hydration, alkalinization of the urine, and catheter drainage can prevent this complication. The other agents given do not display a significantly increased toxicity because of intestinal reabsorption. Methotrexate is the smallest molecule of those listed, and therefore most likely to be absorbed.

Answer 78

4 The questions for this peripubertal boy with intermittent testicular pain are whether he has intermittent torsion and whether the lesion in the testis requires excision. With a normal physical examination; i.e., no horizontal lie to the testis, it is difficult to diagnose intermittent torsion especially since the problem has been evident for only two weeks. The lesion in the right testis is clearly a cyst by ultrasound and treatment for this would be observation with follow-up ultrasound in three months. True simple cysts of the testis are usually non-palpable, usually subtunical near the mediastinum of the testis, and rarely change on follow-up ultrasound. Complex cysts or cysts with calcification tend to be more associated with malignancy and require more aggressive management.

Answer 79

1 The only recommended test prior to surgery, beyond those already mentioned, is a UA. A positive UA may trigger other testing. PSA was normal within the last year and need not be repeated. Cystoscopy, uroflowmetry, and postvoid residual testing are all optional. Cystoscopy may be appropriate if the size of the prostate is in doubt, particularly if it may be too large for endoscopic management. Uroflowmetry, although not specific, may be a reasonable indicator of bladder outlet obstruction. Pressure flow testing is the best assessment for outlet obstruction but is costly, invasive, and not recommended routinely unless the diagnosis is in doubt - for example, younger men with small prostates and severe LUTS, or if there is concern for neurogenic detrusor dysfunction.

Answer 80

3 Urethral carcinoma is more common in women, and may involve either the anterior or posterior urethra. The location of the primary tumor will dictate the primary landing zone. The anterior (distal) urethra and labia drain to the superficial and then deep inguinal nodes, while the posterior (proximal) urethra drains primarily to the external iliac, and then secondarily to the hypogastric and obturator lymph nodes.

Answer 81

5 The likely cause of this child's breakthrough infections is dysfunctional elimination syndrome, which may be present in as many as 20% or more of children with VUR. The enuresis and constipation are indicative of abnormal function. While she may ultimately need reimplantation, it is prudent to attempt to control her voiding dysfunction before undertaking surgical repair. Correction of VUR will not treat the underlying pathology. Her voiding dysfunction includes both bladder and bowel components and both need to be addressed with a timed voiding regimen and effective treatment of constipation. Oxybutynin will exacerbate the constipation and should be used only in refractory cases unresponsive to timed voiding and bowel management.

Answer 82

4 Sixteen-dot plication for correction of Peyronie's disease is a simple and non-extirpative method to straighten the penis. The most common postoperative complaint in a series of 132 patients was penile shortening (41%) followed by suture pain/discomfort (12%), pain with erection (11%), narrowing of the phallus (9%), decreased penile sensation (6%) and hematoma formation (4%).

Answer 83

1 Genetic alterations on chromosome 3 are common in the clear cell variant of RCC but are uncommonly found in the other histologic variants, suggesting distinct pathways to tumorigenesis. The VHL tumor suppressor gene located at chromosomal locus 3p25 is mutated in approximately 50% of clear cell type RCC. The mutations of this gene result in decreased expression of hypoxia inducible factor 1 (HIF1) and increased expression of vascular endothelial growth factor 1 (VEGF1), thereby resulting in increased angiogenesis.

Answer 84

4 A number of recognizable syndromes are associated with an increased incidence of Wilms' tumor. Three syndromes that are well known to be at high risk for Wilms' tumor development include Denys-Drash syndrome (male pseudohermaphroditism manifested by proximal hypospadias and cryptorchidism, membrano-proliferative glomerulonephritis, and nephroblastoma), Beckwith-Wiedemann syndrome (macroglossia, nephromegaly, hepatomegaly) and WAGR syndrome (Wilms' tumor, aniridia, gonadoblastoma, and mental retardation. In patients with Denys Drash syndrome, the kidneys need to be monitored carefully and removed as renal failure occurs.

Answer 85

1 Normal bladder compliance defined as the change in bladder volume divided by the change in detrusor pressure, should be \> 12. Patients with decreased bladder compliance are at great risk for development of upper tract deterioration. The amplitude of phasic involuntary bladder contractions is of little prognostic value due to their transient nature. Detrusor LPP of \> 40 cm H2O is a risk factor for upper tract deterioration however it is not as significant as poor bladder compliance. Neither detrusor areflexia nor increased urethral closure pressures are independent risk factors for hydronephrosis unless associated with elevated storage pressures.

Answer 86

1 This patient has CT scan findings that are pathognomonic of angiomyolipoma. Negative Hounsfield units confirm the presence of fat in this lesion, even though this can only be observed in a small region. No treatment is indicated in an asymptomatic patient with a relatively small angiomyolipoma but follow up with periodic CT scans is appropriate. Extension into the perinephric fat and even lymph node involvement can be found in association with angiomyolipoma and is thought to represent a secondary site of origin rather than a metastatic lesion. The presence of fat on a CT image is diagnostic.

Answer 87

4 The entire two liters of isotonic fluid are lost from the extracellular fluid (ECF). Since the loss is isotonic, the osmolality of the ECF did not change and no water moved out of the cells. The two liters of ingested pure water are distributed throughout the entire body water compartment; one-third remains in the ECF, and two-thirds move into the cells. The addition of pure water lowers the osmolality. Even though the decreased ECF volume would stimulate ADH secretion, the reduced osmolality would inhibit it via the hypothalamic osmoreceptors. Osmoreceptor input usually predominates during such "conflicts" unless the ECF volume depletion is very large. Renin and aldosterone secretions would increase because of the decreased ECF volume.

Answer 88

5 The pharmacokinetic profile of the PDE5 inhibitors differs mainly in terms of the half life, with tadalafil having a significantly longer half life (17.5 hours) than vardenafil or sildenafil (4-6 hours). The other principle difference is in absorption with a concomitant fatty meal. Both vardenafil and sildenafil have decreased absorption with a high fat meal while the absorption of tadalafil is not affected by food consumption. Many studies show that at least four to six attempts may be needed to demonstrate that a patient will respond to PDE5 inhibitors. This patient has had an adequate trial of tadalafil and taking it on an empty stomach would not improve its efficacy. He has already been given the maximum FDA approved dose of tadalafil and increasing his dose will only increase the incidence of side effects. No level one evidence exists that switching PDE5 inhibitors will improve efficacy. Initiating treatment with intracorporal alprostadil would be a reasonable next step to efficaciously treat his erectile dysfunction.

Answer 89

4 Current literature has challenged the classical teaching that oxygen exposure increases the likelihood of pulmonary toxicity in patients treated with bleomycin. In this study the factors associated with postoperative pulmonary problems were positive fluid balance, amount of blood transfused, surgical time, estimated blood loss, and forced vital capacity, while the fraction of inspired oxygen was not a predictor of adverse outcome. Avoiding overhydration was the most important factor in limiting pulmonary problems.

Answer 90

3 Several articles have pointed out that contrast agents may occasionally be toxic, especially in the diabetic or multiple myeloma patient. However, the most important factor in avoiding the development of acute renal failure after intravenous administration of contrast agent is adequate hydration followed by the correct dosage of the contrast agent. Pre-existing cardiovascular disease alone is not a significant risk factor nor is a history of drug allergies or allergic reactions. The presence of diabetes mellitus alone is not a risk factor unless accompanied by dehydration.

Answer 91

2 The prevalence of asymptomatic bacteruria is higher in women with diabetes mellitus. Women with type II diabetes mellitus and asymptomatic bacteruria are at higher risk for developing a symptomatic UTI. However, patients with type I diabetes mellitus and asymptomatic bacteruria are not at higher risk for this occurrence. There are no known risks of developing symptomatic UTIs in HTN or thyroid disorders.

Answer 92

3 A likely cause of late onset nocturnal incontinence following orthotopic ileal neobladder is mucous retention resulting in incomplete bladder emptying. Patients with this condition may still maintain good daytime continence by voluntary contraction of the external sphincter and frequent voiding, but at night pelvic floor relaxation, decreased urethral closing pressure, and hypertonic urine production with an obligate water loss overcome these compensatory behaviors. This problem is best managed initially by catheterization of the pouch to determine PVR irrigating the mucous, and containing optimal drainage of the pouch prior to retiring. If nocturnal incontinence persists, setting an alarm to wake during night can be beneficial.

Answer 93

4 Ischemic necrosis of the augmented bladder wall may result from inefficient bladder emptying and chronic overdistention. Patient noncompliance with intermittent catheterization and mucus plugs may contribute to chronic overdistention, but are not the primary cause for bladder rupture after augmentation cystoplasty. A lack of detrusor sensation, chronic inflammation and the presence of bladder calculi may also be contributing factors. Bladder malignancy following enterocystoplasty is a rare occurrence and not found to be associated with spontaneous bladder perforation.

Answer 94

5 One study identified the major difference between SWL and ureteroscopy for lower pole stones was return to work, specifically 3.3 days following SWL compared to 8.5 days following ureteroscopy. Although SWL arguably provides acceptable first line therapy for stones 1 cm or less based on the initial randomized trial, ureteroscopy has been touted as a promising alternative that can improve the stone free rate with little additional morbidity over SWL. However, in this small trial investigators were unable to validate the hypothesis that ureteroscopy was superior to SWL. The stone free rate after ureteroscopy and SWL for lower pole stones of less than or equal to 1 cm was remarkably low and not statistically different between the two modalities. While the results of the study support that either SWL or ureteroscopy may be used in this situation, practitioners and patients must be cognizant of the limitations of treatment modalities that rely on spontaneous fragment passage to achieve a stone-free state.

Answer 95

1 Most adenocarcinomas of the bladder represent metastases from other primary adenocarcinomas such as colon, breast, or lung cancers. Hence, a primary source other than the bladder must be considered, and this patient should undergo colonoscopy for further evaluation prior to administration of definitive therapy.

Answer 96

3 Although the kidney contralateral to a multicystic dysplastic kidney does exhibit compensatory hypertrophy at birth, this occurs rapidly after birth, and by age two years, the hypertrophied kidney exhibits a GFR significantly greater than one normal sized kidney. This is not correlated with the removal of the multicystic kidney. Studies have demonstrated that compensatory renal growth can begin prenatally. Because the placenta provides the excretory function for the fetus, an increased excretory burden on the kidney is not required to initiate compensatory growth. Rather, alterations in growth factors or inhibitors presumably modulate the prenatal changes. Compensatory increase in renal mass in the adult is largely due to cellular hypertrophy. Neonatal glomerular hypertrophy results also from increased glomerular basement membrane surface area and proliferation of mesangial matrix.

Answer 97

4 To stabilize glycemic control in patients taking insulin, frequent glucose monitoring should be performed, with insulin dosages adjusted appropriately. On the day before surgery, long-acting insulin can be continued throughout the day if the patient's control is good, particularly if the patient is using glargine. Oral agents are generally discontinued before surgery. Long-acting sulfonylureas (e.g., chlorpropamide [Diabinese]) are stopped 48 to 72 hours before surgery, while short-acting sulfonylureas, other insulin secretagogues, and metformin [Glucophage] can be withheld the night before or the day of surgery. No recommendations exist for discontinuation of thiazolidinediones (e.g. rosiglitazone [Avandia], pioglitazone [Actos]) before surgery; their extremely long duration of action probably indicates no rationale for stopping them at all.

Answer 98

4 The normal PSA for a man under 50 is \< 2.5, and in light of the low testosterone, this patient should have a much lower PSA level. Hence, a PSA of 2.1 ng/ml in this setting is suspicious for cancer and a prostate biopsy should be performed. There is no role for a % free PSA estimation, as it will not alter management at this time. Alternatively, the PSA could be repeated after testosterone replacement. It may be risky to initiate exogenous testosterone without ruling out prostate cancer.

Answer 99

3 Pseudostratified columnar epithelium lines the urethra from the membranous area to the fossa navicularis where stratified squamous epithelium becomes predominant. Transitional cell epithelium lines the prostatic urethra to the membranous area. Neither columnar nor keratinized squamous epithelium is normally present in the male urethra.

Answer 100

3 The American Urological Association Nephrolithiasis Guidelines Panel strongly recommends percutaneous nephrolithotomy as first line therapy for management of staghorn struvite renal calculi. The 2005 report of the Guidelines Panel states that all infected stone material should be eliminated to prevent recurrent infection lithiasis. After nephrolithotomy, hemiacidrin irrigation may be used to dissolve residual fragments. SWL for a struvite calculus requires multiple interventions and is unlikely to render the patient stone free. Ureteroscopy similarly is not likely to render the patient stone free. The urease inhibitor acetohydroxamic acid may be used to reduce the urinary saturation of struvite and decrease stone formation, however it should be noted that an increased incidence of DVT has been reported in patients receiving the medication. Ammonium chloride, methenamine hippurate and ascorbic acid have been reported to retard stone formation, but are not used as primary therapy.

Answer 101

1 Complexed PSA represents the fraction of total PSA that is circulating bound to other serum proteins, including antichymotrypsin and alpha-1 macroglobulin. Prostate manipulation including biopsy, cystoscopy, catheterization, and vigorous massage generally result in a transient increase in serum total PSA. Most of the rise in total PSA is contributed by the free (non-bound) component. In general, complexed PSA is the most stable component and relatively little rise occurs following prostate instrumentation. Complexed to total PSA ratio would decrease upon disproportionate free PSA increase. Due to the transient nature of PSA rise with prostate manipulation, PSA velocity is generally not affected.

Answer 102

2 The presence of autosomal recessive polycystic kidney disease varies depending on age. In older children, hepatosplenomegaly due to portal HTN may be prominent and associated with renal interstitial fibrosis and cortical cystic disease. Autosomal dominant polycystic disease does not usually cause renal insufficiency at such an early age; the cysts are variable in size and occur throughout the kidney. Familial juvenile nephrophthisis and renal-retinal dysplasia are associated with renal cysts which are typically located in the medulla but the kidneys are usually shrunken and scarred. Renal cysts do occur in tuberous sclerosis but renal failure is usually attributed to multiple solid angiomyolipomas.

Answer 103

5 The combination of LUTS and bladder pain with negative urine cultures suggest interstitial cystitis. Interstitial cystitis, in the strictest sense is a diagnosis of exclusion. The reason to perform a cystoscopy is to identify urothelial lesions such as carcinoma-in-situ, ulcerative lesions, bladder tumor, tubercular granulomas, or other treatable urothelial lesions. While glomerulations have been thought to be diagnostic for interstitial cystitis, they can only be detected with hydrodistention of the bladder under anesthesia, not routine cystoscopy. A urethral diverticulum, while potentially diagnosable with cystoscopy, is better diagnosed with pelvic MRI scan. Cystitis cystica and squamous metaplasia are common in middle aged women, and require no diagnostic testing or treatment.

Answer 104

1 This patient has significant renal insufficiency and is at risk for further deterioration. There is a growing body of literature regarding the endourologic management of upper-tract TCC in this situation. Indeed, this patient is an ideal candidate for an endourologic approach given the need for renal parenchymal preservation and low grade non-invasive tumor. From a tumor standpoint there is a very low risk of progression. With close follow-up, recurrences can be treated by repeat endourologic techniques. Intravesical or percutaneous BCG is not indicated at this time as is supported by only anecdotal evidence.

Answer 105

5 The femoral triangle, also known as Scarpa's triangle, is bounded laterally by the medial margin of the sartorius. The medial boundary is the adductor longus and the inguinal ligament is superior. The floor of the triangle is composed of the pectineus muscle medially and the iliopsoas laterally. The location of the saphenofemoral junction is estimated to be at a point two fingerbreadths lateral and two fingerbreadths inferior to the pubic tubercle. These landmarks are important in a lymphadenectomy for penile cancer.

Answer 106

1 A ureteral injury occurs in 1% of gynecological procedures. This usually results from failure to identify the ureter when attempting to obtain hemostasis. Provided there is a clear surgical field, ureteral injury due to confusing it with another structure or during occlusion of the uterine or ovarian vessels is distinctly unusual.

Answer 107

3 Immediate administration of intravesical agents following initial TURBT has been postulated to decrease tumor reimplantation and provide immediate therapeutic efficacy for microscopic residual disease. A number of randomized clinical trials have shown that TUR followed by immediate administration of a single dose of mitomycin C reduces recurrence rates when compared to TUR alone. These studies have also demonstrated that this effect is lost if administration is delayed by a day or more after TUR.

Answer 108

1 Urine volume is the difference between GFR and amount of water resorbed. If a normal adult has a GFR of 180 liters/day then 179 liters must be reabsorbed to have a urine volume of one liter. Anuria is described as urine volume that is virtually nil, i.e., less than 50 ml/day. Oliguria is substantially reduced urine volume (less than 30 ml/hour). Urine sodium concentration is usually below 25 mEq/l in volume depletion and above 40 mEq/l with normovolemia or acute tubular necrosis. A urinary sodium of only 8 mEq/l is most suggestive of prerenal azotemia. RTA and chronic pyelonephritis would not generally lower urinary sodium concentrations.

Answer 109

3 The best initial treatment of GU tuberculosis is triple drug treatment for two months followed by two drugs for four months. The best combination is INH, rifampin, and pyrazinamide. If the INH resistance is above 4% in the patient's community, addition of ethambutol or streptomycin to the three drugs is advised. In 1991, resistance to one or more antituberculosis drugs was noted in 14.2% of patients with tuberculosis in the United States; 9.5% of patients had resistance to isoniazid or rifampin. Drug resistant tuberculosis has an increased prevalence in patients who are HIV-positive and among people who counsel HIV patients . Isolated isoniazid- resistant tuberculosis infections should be treated with rifampin, pyrazinamide, and ethambutol for six months. For patients who have tuberculosis strains that are resistant to rifampin, an alternate regimen of isoniazid and ethambutol for 18 months or isoniazid, pyrazinamide, and streptomycin for nine months are recommended.

Answer 110

3 Intravesical BCG is generally well-tolerated, but patients should be monitored for systemic infection with BCG and treated appropriately. In the absence of bacteruria, patients with persistent (\> 24 hours) high fevers (\> 38.5°C) that do not respond to antipyretic therapy, should have BCG treatment discontinued and INH therapy started. This may be an early sign of a systemic BCG infection. Double and triple therapy is reserved for patients who present with pulmonary or hepatic involvement with BCG.

Answer 111

4 Approximately half of the children on CIC have chronic bacteriuria. Despite suppressant antibiotic therapy, the majority of these patients continue to have chronic bacteriuria and suppressant therapy often leads to colonization with more resistant strains. Children on CIC who are clinically well without evidence of pyelonephritis or reflux require no treatment for chronic bacteriuria. Cystoscopy holds no value in this circumstance. Sterile intermittent catheterization has not been shown to decrease bacteriuria consistently when compared to clean CIC. Intravesical antibiotics are also uncertain in terms of benefit in this circumstance and are not even considered unless the child is suffering consequences of recurring symptomatic UTI and has failed other approaches.

Answer 112

4 The patient has oligospermia. No correctable abnormalities are present. Further evaluation with ultrasonography for a subclinical varicocele is not helpful. Since two semen analyses show the same defects, a repeat semen analysis will be of no value. If the two analyses were discrepant, another specimen would be useful. No indication for antisperm antibody testing is present. Intrauterine insemination is most effective for cervical-factor infertility or isolated oligospermia.

Answer 113

2 The discovery of the VHL gene and subsequent elucidation of the dysregulated tumor pathways in RCC has led to targeted therapy for this disease. Recently the FDA has approved sorafenib (Nexavar) and sunitinib (Sutent) for the second-line treatment of advanced RCC after failed cytokine therapy. The fast-track approval of sorafenib was in large part due to the preliminary results of a large randomized trial conducted in over 100 centers in 19 countries. In a planned preliminary analysis, sorafenib doubled the progression-free survival compared to placebo and was associated with a greater than 50% reduction in the risk of progression. The trial was designed to determine whether treatment provides an overall survival benefit and analysis of this endpoint is premature. Although major tumor responses including complete responses are rare with this drug, the majority of patients exhibit tumor regression. These drugs are synthetic small molecules that inhibit a number of kinases important in tumor cell proliferation and tumor angiogenesis. Supportive care and hospice referral would be premature in this patient. Although gemcitabine based-chemotherapy regimens show activity and are being studied in kidney cancer, their role is in patients with rapidly progressing disease and unusual histologies including sarcomatoid, collecting duct, and renal medullary carcinoma. Other cytokine therapy following failure of high-dose IL-2 is rarely beneficial. Allogeneic stem cell transplant to produce a graft vs. tumor response is highly experimental and conducted in only a few centers in preliminary clinical trials.

Answer 114

2 The neonatal serum creatinine of 1.2 mg/dl reflects maternal creatinine and is not a matter of concern. Maternal diabetes mellitus (insulin-dependent) poses an increased risk for sacral agenesis and bladder dysfunction in the infant. Maternal HTN is associated with some risk of renal vein thrombosis. Some infants do not pass urine in the first 24 hours. At 20 hours, no studies are indicated in the absence of other problems. Multicystic kidney is congenital, but not hereditary.

Answer 115

3 Extrinsic ureteral obstruction is associated with stent failure in nearly half of patients within a year. A recent study of 101 patients treated with indwelling stents revealed extrinsic obstruction due to cancer; renal insufficiency (serum creatinine \> 1.3 mg/dl); and obstruction following XRT or chemotherapy were predictors of stent failure. Patients with metastatic disease requiring systemic therapy may be best served with a percutaneous nephrostomy rather than a ureteral stent. Other alternatives, such as an extra-anatomic nephrovesical stent, can be considered as well.

Answer 116

5 LUTS are common following brachytherapy and often seem to coincide with the half-life of the isotope (60 days for iodine-125 and 17 days for palladium-103). Usually these symptoms improve over time and respond to alpha-blocker therapy. Patient selection for brachytherapy is extremely important to avoid severe voiding dysfunction and urinary retention. Patients with significant pretreatment symptoms despite medical therapy are poor candidates for an implant as they are much more likely to have severe post-implant LUTS and a higher risk for urinary retention. In brachytherapy series, 2-8% of patients require TURP often within the first six months postimplant because of urinary retention. TURP should be delayed at least three months after the initial seed implantation. The resection should not be aggressive with preservation of apical tissue. Prior to three months, retention is best managed by CIC. Finasteride and leuprolide acetate would require months before any possible benefit and would not be effective in a patient with a small gland. A suprapubic catheter would provide drainage but has the associated problems of infection and bladder irritation. TUMT is contraindicated following radiation therapy.

Answer 117

1 The genitofemoral nerve penetrates the body of the psoas muscle at about L3/L4 where it travels caudally along its surface and is vulnerable to suture injury. The other nerves are all lateral or dorsal to the psoas muscle and removed from the operative site.

Answer 118

2 Azoospermic men have an increased incidence of chromosomal abnormalities. Patients thought to have non-obstructive azoospermia should have both a karyotype and Y-chromosome microdeletion analysis. Of the three types of Y chromosome deletions, types a and b rarely if ever have sperm production in the testicles. Type c deletions have patchy sperm production in the testicles some of the time. The latter may benefit from testicular sperm retrieval but the types a and b deletions will likely not. With an FSH three times normal this patient will not have obstructive azoospermia and thus scrotal exploration and a vasogram are not indicated. Fine needle testicular aspiration for diagnosis is unnecessary. Both needle aspiration and testicular microdissection and cryopreservation of sperm are premature without prior genetic testing. In addition needle aspiration is less successful in retrieving sperm from non-obstructed azoospermic patients than open testicular sperm extraction. Semen fructose determination may demonstrate a low fructose concentration in patients with ejaculatory duct obstruction or congenital bilateral absence of the vas deferens. Both of these conditions are associated with low volume acidic semen specimens which are not present in this patient.

Answer 119

1 This rounded non-enhancing lesion of the kidney is consistent with a hyperdense cyst. Hyperdense cysts are characteristically more dense than the kidney on noncontrast imaging (typically up to 80 HU) and do not enhance upon contrast administration. In this case, the increase in density of 3 HU is not significant and suggests a nonenhancing lesion. The history of melanoma should lead the clinician to be suspicious of a metastatic lesion, and if the mass were enhancing, needle biopsy would be indicated prior to resection.

Answer 120

4 The management of the infant with a PUV depends on the severity of the obstruction and the degree of any renal dysplasia present. The main problems arise in management of the infant with severe obstruction and compromised renal function with dehydration, acidosis, and sepsis. Initially, a small infant feeding tube, placed transurethrally, can provide bladder drainage. Once stabilized, valve ablation can be undertaken. Vesicostomy is reserved for infants who cannot undergo primary valve ablation because of the inadequate size of their urethra or for very small, unstable infants. If initial bladder level drainage does not result in satisfactory clinical improvement, temporary supravesical diversion may be considered, however the vast majority of these patients will be found to have renal dysplasia, not urethral vesical obstruction as the etiology the penile of the persistently elevated creatinine.

Answer 121

4 Clinically, RTA is associated with recurrent urolithiasis, calcium phosphate stones, medullary sponge kidney, nephrocalcinosis, hypocitraturia, hypokalemia, metabolic acidosis and urine pH greater than 5.5. Hypocitraturia is the most important metabolic factor for stone formation in type 1 (distal) RTA although hypercalciuria can occur. Potassium citrate (or bicarbonate) corrects the systemic acidosis and normalizes urinary citrate. If hypercalciuria persists in spite of alkali therapy, thiazides should be added.

Answer 122

4 The site of the stoma should be selected preoperatively. This is done with the patient in a sitting and supine position. Care is taken to place the stoma over the rectus muscle at least 5 cm from the planned incision line. The point chosen should be well away from any skin creases, scars, the umbilicus, belt lines or bony prominences. All stomas should be placed through the belly of the rectus muscle located at the peak of the infraumbilical fat roll. If the stoma is placed lateral to the rectus sheath, a parastomal hernia is likely to occur.

Answer 123

3 DMSA is bound to renal proximal tubule cells in progressive amounts over three to six hours. Over time, there will therefore be less background activity and a higher tissue to background ratio. This is particularly important with poorly functioning kidneys. MAG-3, DTPA and Hippuran are all excreted. Functional assessment is done in the first three minutes after injection, during which time there is considerable background activity. Glucoheptonate is a hybrid that is both excreted and bound.

Answer 124

3 Epidemiologic studies have demonstrated that low calcium and increased animal protein consumption place an individual at risk to develop nephrolithiasis. Metabolic studies have demonstrated that increased sodium consumption results in increased calcium excretion and low calcium intake results in increased oxalate excretion. Borghi and associates studied men with recurrent calcium oxalate nephrolithiasis associated with hypercalciuria. Patients were randomized to one of the following diets: 1) low animal protein, 2) low calcium, 3) low sodium, and 4) normal sodium. Only patients on low sodium and normal calcium diet had a decreased incidence of stones. This finding, plus the knowledge that increased intake of a animal protein increases the risk of stones, results in the recommendation that patients with hypercalciuria should be placed on diets low in sodium and animal protein with normal calcium intake.

Answer 125

4 Prostate MRI scan, especially with combined endorectal and phase-array coils, is used in prostate cancer staging with up to 82% accuracy. The T1- and T2-weighted images are helpful in differentiating between postbiopsy hemorrhage, which presents as a high T1 and a low T2 lesion, and prostate cancer, which presents as a low T1 and low T2 lesion.

Answer 126

1 Severe hyperkalemic cardiotoxicity must be treated immediately, not by lowering serum potassium concentration alone but preventing cardiac excitability and antagonizing the cardiotoxic effects of hyperkalemia. Thus, I.V. calcium gluconate is the initial treatment of choice. This must be followed by measures to immediately lower serum potassium since the duration of calcium effects are brief. Bicarbonate and glucose should be given next, but they are short-acting and exchange resins/dialysis should be planned for more long-term treatment.

2010 Flashcards

(150 cards)