Pediatric GU Flashcards

Question

79) On antenatal ultrasound scan, oligohydramnios, non-visualization of the urinary bladder and bilateral enlarged hyperechoic kidneys are recorded. Renal failure ensues within the first month of life. An older sibling aged 5 years has established portal hypertension. The parents are phenotypically normal. What are the odds of further offspring of the same parents having the same disease? a. zero b. 1 in 5 c. 1 in 4 d. 1 in 2 e. unity

Answer 1

c. 1 in 4 Infantile polycystic kidney disease is autosomal recessive. Both parents and half the children will be carriers. The sonographic hallmark is enlarged echogenic kidneys. The individual cysts are small, measuring 1–2 mm, and can be defined only with a high-resolution probe. Autosomal kidney disease affects the liver also. The less severe the renal disease, the more severe the hepatic periportal fibrosis.

Answer 2

b. left ureteral duplication The ‘drooping flower’ appearance on IVU occurs with a duplicated system when the obstructed dilated upper pole collecting system displaces the contrast-opacified, lower collecting system laterally and inferiorly. The Weigert–Meyer rule describes the commonest relationship of insertion of the duplicated ureters into the bladder. The upper collecting system ureter inserts ectopically into the bladder inferior and medial to the orthotopic ureter, which enters the bladder near the trigone. The ectopic ureter may be stenotic or obstructed with or without ureterocele

Answer 3

b. large hyperechoic medullary pyramids The average length of the normal neonatal kidney is 4.5 cm. Ultrasound appearances of the kidney in the neonate and infant show a number of differences from those of the older child and adult. Cortical echogenicity is increased, as the glomeruli form 20% of the cortex in the neonate but only 9% in the adult, and may be comparable to that of the liver or the spleen. The medullary pyramids are larger and more hypoechoic than in older children and adults, and there may be little or no fat in the renal sinus. Persistent fetal lobulation may give the kidneys a lobulated contour. In addition, echogenic septa may be normally seen at the anterosuperior or posteroinferior margins of the kidney, representing the sites of fusion of metanephric elements. Most kidneys attain an adult pattern by 6 months of age

Answer 4

b. transverse vaginal septum Haematometrocolpos is described, which at this age can be due to a transverse vaginal septum or imperforate hymen. There is an association with imperforate anus, hydronephrosis, renal agenesis and dysplasia, polycystic kidneys, duplication of the vagina and uterus, sacral hypoplasia and oesophageal atresia. Cervical dysgenesis and obstructed uterine horn would produce haematometra.

Answer 5

(b) Pelvi-ureteric junction obstruction The most common causes of antenatal hydronephrosis (regardless of gender), in order of decreasing frequency are: PUJ obstruction (22%), posterior urethral valve (18%), ectopic ureterocoele (14%), Prune-belly syndrome (12%), and VUJ obstruction (8%)

Answer 6

(d) Mass invades into the IVC Classically neuroblastoma encases vessels, whereas Wilm's tumours may invade vessels. Calcification is more common in neuroblastoma (85-95%) than Wilm's (15%), neuroblastoma commonly crosses the midline, only 10% of Wilm's tumours are bilateral. Neuroblastoma typically metastasises to bone and lymph nodes; Wilm's to the liver, lungs and lymph nodes.

Answer 7

(b) Cerebellar ataxia Cerebellar ataxia is associated with neuroblastoma. Wilm's is associated with WAGR (includes duplex/ horseshoe/ fused kidneys), Drash syndrome (male pseudo-hermaphroditism), and BeckwithWiedemann syndrome (macroglossia). It is also associated with spontaneous aniridia and hemihypertrophy

Answer 8

(b) Neurogenic bladder Anorectal malformation may be low (commonest), intermediate, or high, depending on the relation to the levator sling. High malformations are associated with fistulas and a high association with GU (50%), and VACTERL anomalies. History of surgical repair makes fistulas unlikely; post-op patients often suffer urinary incontinence; the additional association of spinal anomalies make neurogenic bladder (which predisposes to UTI) a likelihood. There is no association with PUJ obstruction or urethrocoele.

Answer 9

(d) Stage IV Stage I limited to organ of origin. Stage II regional spread, but does not cross midline. Stage III tumour extends across midline, or is a unilateral tumour with contralateral LNs. Stage IV: the tumour has spread to distant lymph nodes, bone, bone marrow, liver, skin or other organs. Stage 1IV-S is a subset of neuroblastoma in infants < 1 year with a good prognosis

Answer 10

(e) Horseshoe kidney Horseshoe kidneys are associated with other renal anomalies in 50%, and non-GU system anomalies in 30% (GI, cardiac, skeletal). In 90% of crossed ectopia there will be fusion (crossed-fused ectopia); associated anomalies are rare. Ask-Upmark kidney shows segmental hypoplasia; there is controversy over whether it is a congenital anomaly or a sequelae of severe pyelonephritis. In the cited reference, no patients with duplex kidneys were found to have non-GU related anomalies.

Answer 11

(e) Renal lymphangiectasia Although rare, renal lymphangiectasia has a characteristic imaging appearance resulting from the failure of the renal lymphatic tissue.

Answer 12

(c) No imaging Recent NICE guidelines recommend no imaging for simple (nonatypical) first UTls in infants 6 months - 3 years and children over 3 years which respond to antibiotics within 48 hours. In children over 3 years with an atypical UTI, an US should be urgently arranged, in those with recurrent UTls a 6 week US and 6 month DMSA scan should be arranged; there is no role in this age group for MCUG. An US is always performed in those < 6 months old (routinely at 6 wks), if this is abnormal, or there is an atypical organism, or recurrent UTls, MCUG is performed. MCUG may be considered in those 6 months – 3 years if there is pelvic dilation on US, or a family history of VUR

Answer 13

(d) Juvenile autosomal recessive PKO ARPKD is associated with liver fibrosis and portal hypertension. The degree of hepatic fibrosis is inversely related to the degree of renal disease. The relative involvement is: antenatal (90%; renal disease; minimal hepatic fibrosis), neonatal (60%; mild fibrosis) infantile (20%; moderate fibrosis) and juvenile (10%; gross liver fibrosis). Juvenile type is postulated to be a primary hepatic fibrosis rather than an ARPKD.

Answer 14

(a) The incidence at autopsy is 1:2,000 It is the commonest fusion abnormality and is seen in 1:400 patients at autopsy. It can be complicated by obstruction, reflux or stone formation. The isthmus can contain functioning renal tissue.

Answer 15

(e) Prune-belly syndrome Prune-belly syndrome is a triad of absent/ deficient abdominal muscules, renal dysplasia (bilateral hydroureters/ hydronephrosis), and cryptorchidism. Due to the associated absence of the prostate gland, the posterior urethra is often dilated proximally - the entire urethra may be dilated. PUVs are a key differential, but the implied abdominal wall defect, thin-walled bladder, and cryptorchidism go against this. MMH causes insufficiency of the abdominal viscera, but occurs in females. Rhabdomyosarcoma would be unusual antenatally.

Answer 16

(b) Trabeculated low capacity bladder The classical triad of prune-belly syndrome is abdominal wall defect/ weakness, bilateral cryptorchidism and genito-urinary abnormalities. Typically, a thickened, non-trabeculated, large volume bladder is seen. Non GU abnormalities affecting the lungs (CCAM, lung hypoplasia), musculoskeletal system (scoliosis, pectus excavatum), cardiovascular (VSD, PDA, Fallots) and GI system (Hirschprung's disease, malrotation) are also seen

Answer 17

(e) Proptosis The features described would suggest a diagnosis of Wilm's tumour which has a number of associations including Beckwith-Wiedemann syndrome, sporadic aniridia, hemihypertrophy and other genitourinary abnormalities including Drash syndrome. Proptosis can be seen in neuroblastoma.

Answer 18

(d) Stage IV Stage I: tumour limited to the kidney. Stage II: extension into the perinephric space +/-vessel invasion. Stage III: LNs in the abdomen or pelvis, or peritoneal invasion. Stage IV: haematogeneous spread to lung/ liver/ brain/ bone, or to LNs outside the abdomen or pelvis. Stage V: bilateral renal tumors at diagnosis.

Answer 19

(a) Mesoblastic nephroma Mesoblastic nephroma is the most common solid intrarenal mass in the neonate. 90% present within the 1st year (most by 3 months). It is benign, but there is a risk of sarcomatous degeneration·. Wilm's tumour is commoner in older infants; neuroblastoma is the commonest abdominal malignancy in neonates.

Answer 20

(d) Palpable abdominal mass The commonest presenting features of Wilm's tumour are: palpable mass (90%; 12 cm is the mean diameter at diagnosis), hypertension (50%), pain (35%), anorexia (15%), fever (15%) and haematuria (5%).

Answer 21

(b) Right grade I, left grade II Grade I - reflux into ureter. Grade II - reflux into the ureter/ pelvis/ calyces; no dilatation. Grade III - moderate dilatation with minimal blunting of the fornices. Grade IV - moderate ureteral tortuosity and obliteration of the fornices. Grade V - gross dilatation with tortuous ureter.

Answer 22

(c) Neuroblastoma Although some of the imaging features may overlap between these conditions, the history is highly suggestive of neuroblastoma. Intractable diarrhoea is secondary to elevated levels of VIP.'· Hypertension suggests the presence of increased catecholamine (VMAand HVA) production.

Answer 23

(a) Inguinal canal The inguinal canal is the commonest site for an undescended testis, although it can lie anywhere along its embryological passage from kidney to scrotum. Ectopic testes can be found in the femoral canal, perineum, contralateral hemiscrotum or prepubic space. Localisation is important as, if present, there is a greatly increased risk of malignancy

Answer 24

(b) Increased number of calyces in the left kidney compared to the right Asymmetrical renal size may be the only US finding with a duplex system. The 'Weigert-Meyer' rule states that the lower pole ureter inserts in the normal position, the upper pole ureter inserts inferiomedially, tends to be stenotic and obstructed and is often associated with a ureterocoele. The lower ureter is prone to VUR. The renal pelvis will have a concave upper border due to inferior displacement by the · obstructed upper pole, there is lateral displacement of the kidney and ureters and there are decreased calyces in comparison to the normal side, producing the 'drooping lily' sign.

Answer 25

(d) Multicystic dysplastic kidney MCKD is normally unilateral (bilateral in 5-20%) and is thought to be caused by pelvi-infundibular atresia. US shows multiple cysts of variable size that are randomly arranged and are separated by little or no parenchyma; a renal pelvis cannot be seen. It is the 2nd most common cause of a neonatal abdominal mass (after hydronephrosis) and is the most common renal cystic disease in infants. Meckel-Gruber syndrome produces enlarged polycystic (2-10 mm cysts) kidneys in utero, and typically causes oligohydramnios and pulmonary hypoplasia. MLCN is characterised by large(> 10 cm) cystic spaces, which will compress or displace the parenchyma.

Answer 26

(d) Right adrenal haemorrhage Neonatal causes include dehydration (vomiting, diarrhoea), sepsis, birth trauma and prematurity. Glycosuria in infants of diabetic mothers is another cause, ~md there is an association with increased maternal age. Left adrenal haemorrhage is a cause of RVT; the lt adrenal vein drains to left RV, the right adrenal drains directly to IVC.

Answer 27

(b) Enuresis is less likely in female patients In men the upper moiety ureter always inserts proximal to the external urethral sphincter, thus enuresis is less likely. By way of contrast, in females the upper moiety ureter commonly inserts distal to the sphincter, making enuresis more likely. Drooping lily sign refers to IVU obstructed upper moiety ureter displacing lower ur inf.

Answer 28

(d) Neuroblastoma Neuroblastoma is the commonest solid abdominal mass in infants. Itis characterised by difficulty in defining it separately from the kidney, the presence of coarse stippled calcification and the fact it crosses the midline. It may arise from any site within the sympathetic neural chain.

Answer 29

(e) Meckel-Gruber syndrome Meckel-Gruber syndrome is a cause of multiple renal cortical cysts but is invariably fatal at birth due to a combination of lung hypoplasia and renal failure.

Answer 30

(c) Retrocaval ureter Retrocaval ureter is due to a rare embryological failure of IVC formation with persistence of the right posterior cardinal vein and failure of the right supracardinal system to develop. It may be asymptomatic or cause varying degrees of proximal hydroureter.

Answer 31

7. d. Multicystic dysplastic kidney These features are highly suggestive of multicystic dysplastic kidney. The condition is invariably fatal if bilateral, but often asymptomatic if unilateral. It is the second commonest cause of a palpable abdominal mass in the neonate, second only to hydronephrosis. The key features are that no normal renal tissue is present, the cysts do not communicate with each other and they are separated by septae.

Answer 32

8. c. Lung metastases Lung metastases are rare in neuroblastoma and are seen in only 10% of cases, whereas they are seen in 85% of metastatic Wilms tumours. Wilms tumours tend to displace rather than encase the vessels, and intrinsic mass effect, rather than displacement of the kidney, is seen. Calcification is seen in 90%of neuroblastomas but only 10% ofWilms tumours. Wilms tumours are the most common abdominal neoplasmin children between one and eight years of age. It typically presents with an asymptomatic abdominal mass but pain, haematuria and fever may be found.

Answer 33

18. e. Stage IVs The tumour should be staged as stage IVs. This stage refers specifically to patients less than one year of age with no crossing of the midline and disease confined to the liver, skin and bone marrow without radiographically evident skeletal metastases. It confers a good prognosis. Stage I is tumour confined to the organ of origin, stage II includes regional spread not crossing the midline, stage III is extension across the midline and stage IV includes metastatic disease.

Answer 34

19. b. Pelvic–ureteric junction obstruction Hydronephrosis is a common cause of a palpable abdominal mass in children. The most common cause of hydronephrosis is pelvic–ureteric junction obstruction, followed by posterior urethral valves and ectopic ureterocoele. Pelvic–ureteric junction obstruction is usually due to a functional abnormality of the ureteric musculature and is found more commonly on the left than the right.

Answer 35

20. a. Posterior urethral valve Posterior urethral valve is a congenital disorder characterised by a thick mucosal fold located in the posterior urethra. It is the most common cause of bilateral urinary tract obstruction in boys. It is most commonly discovered in the neonatal period, but very occasionally may present into adulthood. Diagnosis is usually made with ultrasound and surgical treatment is indicated.

Answer 36

34. b. Mesoblastic nephroma Mesoblastic nephroma is the most likely diagnosis. This is the most common solid renal neoplasm in the neonate. Although definitive diagnosis with CT or ultrasound is difficult, certain features make the diagnosis more likely; it displays infiltrative growth without involvement of the vascular structures or collecting system (differentiating it from Wilms tumour) and only very rarely calcifies (differentiating it from neuroblastoma).

Answer 37

57. c. Retrocaval ureter Medial deviation of the ureter is seen with retrocaval ureter on the right side and with retroperitoneal fibrosis. The other conditions listed all cause medial deviation of the ureter in the lumbar region. Retrocaval ureter is a rare entity which is caused by abnormal embryogenesis of the IVC. There may be symptoms of right ureteral obstruction and recurrent urinary tract infections.

Answer 38

59. b. Tc-99m DMSA scintigraphy DMSA scan is static renal scintigraphy. There is uptake in the proximal convoluted tubules with 50% uptake within two hours and no significant excretion in this time. Excellent images of the cortex can therefore be gained, making it a good investigation for detection of renal scarring. DMSA and MAG-3 provide more functional information.

Answer 39

60. d. Haemolytic-uraemic syndrome Haemolytic-uraemic syndrome is the commonest cause of acute renal failure in children needing dialysis.

Answer 40

ANSWER: C A micturating cystogram is indicated if the infant is under the age of 6 months, but is not a requirement if the infant is > 6 months unless there is an abnormal US or DMSA.

Answer 41

E Multicystic dysplastic kidney disease (MCKD)

Answer 42

D Micturating cystourethrography The history suggests posterior urethral valves. The most appropriate first line imaging is a micturating cystourethrogram with oblique views.

Answer 43

E Wilms' tumour Wilms’ tumours are associated with nephroblastomatosis; however, nephroblastomatosis is nonenhancing

Answer 44

D The upper moiety ureter is prone to ureteric obstruction.

Answer 45

A Hydronephrosis Over half of abdominal masses originate from the genitourinary tract. Hydronephrosis makes up 25% of these. A multicystic dysplastic kidney makes up about 15%; the remaining diagnoses rarely present as cystic masses.

Answer 46

C Multicystic dysplastic kidney The fact that the condition is unilateral and detected during the antenatal scan makes C the most likely diagnosis. The remaining diagnoses are most often bilateral or diagnosed later in life.

Answer 47

B Establishing divided renal function Indications for a DTPA scan also include follow-up of renal transplant, renography with captopril stimulation and postoperative evaluation of a collecting system.

Answer 48

E The AP renal pelvis measures greater than 50% of the longitudinal length of the kidney. RPD is diagnosed when there is calyceal dilatation with a renal pelvis that measures greater than 5 mm in the second trimester or 10 mm in the third trimester. No ureteric dilatation should be seen.

Answer 49

B In crossed fused ectopia, both ureters enter the bladder in a normal Position Horseshoe kidney is the most common fusion abnormality and arises when both lower poles have fused together. Crossed fused ectopia occurs when one kidney is displaced across the midline and fused inferiorly to the other kidney, but both ureters enter the bladder in a normal position

Answer 50

C The ureter draining the upper moiety usually enters the bladder as a ureterocoele. The upper ureter usually enters as an ureterocele, but the lower pole ureter is the one more frequently affected by reflux. Reflux is rarely seen to the upper moiety.

Answer 51

C Pulmonary metastases are more suggestive of Wilms’ tumour. Calcification on CT is seen in up to 85% of children with neuroblastoma and bone metastases are also more common with this tumour. It is usual for both tumours to enhance less than the surrounding renal parenchyma and neuroblastomas tend to encase vessels, rather than displace them

Answer 52

4. C. Severe renal compromise is the immediate cause of death in the perinatal group. The incidence of autosomal recessive polycystic kidney disease (ARPKD) is approximately 1:20,000 births. It is a disease of tubular ectasia and fibrosis that results in bilateral enlarged kidneys, with loss of cortico-medullary differentiation and multiple small radially arranged cysts. ARPKD is associated with congenital hepatic fibrosis, the severity of which is inversely proportional to the renal abnormality. Four distinct groups of ARPKD are recognized based on age at presentation: perinatal, neonatal, infantile, and juvenile. The most severe renal involvement is seen in the perinatal group. In this group, severe renal impairment results in reduced urine output, oligohydramnios, and pulmonary hypoplasia. Severe respiratory compromise is the immediate cause of death in these patients. Oligohydramnios is also associated with Potter facies (low set and flattened ears, short and snubbed nose, deep eye creases, and micrognathia) and clubfoot deformity.

Answer 53

44. A. Inguinal canal. The testes form in the retroperitoneum and descend through the inguinal canal into the scrotum. Failure to descend is known as cryptorchidism. A cryptorchid testis may be located at any point along the descent route. The most common location is the inguinal canal (70% of cases) followed by the prescrotal region, just beyond the superficial inguinal ring. On ultrasound, it is usually smaller and hypo or isoechoic compared to the normally located testis. Cryptorchidism is associated with an increased risk of malignancy even after correction.

Answer 54

6. C. Grade 3. Whilst most commonly associated with congenital reflux in children, acquired reflux is also seen, most commonly due to bladder outlet obstruction or recurrent cystitis. Grade 1 reflux demonstrates reflux into the ureter, grade 2 has reflux into the pelvicalyceal system, grade 3 as described, and grade 4 is as grade 3 but with increased pelviureteric dilatation and calyceal blunting, and with persisting papillary impressions. Grade 5 demonstrates a markedly dilated pelvis and tortuous ureter with obliteration of the forniceal angles and papillary impressions.

Answer 55

9. D. The upper moiety ureter is associated with ureterocele whereas the lower moiety ureter is associated with vesicoureteric reflux. Ectopic ureter results when the ureteral bud fails to separate from the Wolffian duct and as a consequence is carried more caudally than normal. In females, the ectopic ureter can insert distal to the external sphincter, resulting in incontinence. Approximately 70% of ectopic insertion is associated with complete ureteral duplication. According to the Weigert–Meyer rule of complete ureteral duplication, the ureteric orifice of the upper moiety inserts into the bladder medial and inferior to the lower moiety. The ureter draining the Upper moiety is associated with Ureterocele and Obstruction (note the vowels), whereas the lower pole moiety is associated with vesico-ureteric reflux. The obstructed upper moiety may not be visualized on IVU. The absence of upper pole calyx and displaced (‘drooping lily’) lower moiety calyces help in making the diagnosis.

Answer 56

12. D. Eagle Barrett syndrome. Eagle Barrett syndrome or prune belly syndrome is classically defined as a triad of partial or complete absence of abdominal musculature (resulting in bulging flanks), cryptorchidism, and urinary abnormalities as described above. In addition a number of respiratory, GI, musculoskeletal, and cardiovascular anomalies are associated with this syndrome. It occurs almost exclusively in males. The cause and embryogenesis remain controversial. Bladder outlet obs, mesodermal arrest, and dysgenesis of the yolk sac have been proposed as possible causes.

Answer 57

18. C. 123I-metaiodobenzylguanidine (MIBG) scan. Owing to the high specificity and sensitivity in neuroblastoma, MIBG imaging has superseded the use of 99mTc bone scans for the detection of skeletal metastases in the majority of children with neuroblastoma, which take up the tracer in >90% of cases, and has been recommended by the last international consensus conference as a standard element of staging and response evaluation. False-negative scans may be observed in approximately 10% of neuroblastomas that do not concentrate MIBG. In addition, very small amounts of bone marrow tumour will often not be detected and therefore the MIBG scan must be supplemented with bilateral bone marrow biopsy. For those patients whose tumours are negative for MIBG uptake at diagnosis, the 99mTc MDP bone scan is the standard test recommended to evaluate skeletal metastases. However, the low specificity of this test and the difficulty in interpreting uptake in young children with actively growing bones make investigation of alternative methods preferable. Whole-body MRI is also a sensitive test for neuroblastoma tumours, including bone and bone marrow metastases, although the specificity is much lower than for MIBG. MRI and CT are appropriate in the staging of neuroblastoma, but for the assessment of local invasion rather than bony involvement in particular. There currently is no consensus about the optimal imaging modality for assessing local disease. Both MRI and CT are routinely used, depending on local availability and the radiologist’s preference. 18-FDG PET-CT imaging is not as sensitive as MIBG imaging for bony metastases, although it may be more sensitive for small soft tissue tumours & nodal metastases. The use of PET-CT is not at present well defined and delivers a high radiation dose.

Answer 58

28. D. Enlarged, calcified adrenals that maintain their normal triangular configuration. Wolman disease is a rare, autosomal recessive, primary familial xanthomatosis with involvement and calcification of the adrenal glands. Deficiency of acid esterase or acid lipase results in lipid deposition in multiple organs, including the liver, spleen, lymph nodes, adrenal cortex, and small bowel. It has a poor prognosis. Most patients die within 6 months of life due to malabsorption. All the above-mentioned features are noted in Wolman disease but the most specific finding is enlarged, calcified adrenal glands that maintain their normal configuration.

Answer 59

38. C. Meckel Gruber syndrome. All of the mentioned conditions are associated with multiple renal cysts, but the triad of bilateral enlarged cystic kidneys, occipital encephalocele, and polydactyly is diagnostic of Meckel Gruber syndrome. Bardet-Biedl syndrome is associated with enlarged cystic dysplasia of the kidneys with polydactyly.

Answer 60

52. C. Vesico-ureteric reflux. The abnormality described on ultrasound is multicystic dysplastic kidney (MCDK). It is the most common form of cystic disease in infants and the second most common cause of an abdominal mass in a neonate (after hydronephrosis). Obstruction/atresia of the ureter during the developmental stage is thought to be the etiology. Bilateral MCDK is uncommon, but associated anomalies of the contra-lateral kidney are seen in up to 50% of cases. Vesico-ureteric reflux (30–40%) is the most common associated anomaly, followed by pelvi-ureteric junction obstruction (10–20%)

Answer 61

53. C. The pudendal nerve and internal pudendal vessels pass through the lesser sciatic foramen. There are several potential pathways of extrapelvic spread of pelvic disease. Lateral extension into the gluteal region occurs through the sciatic foramina. It is important to identify extrapelvic spread, as combined transabdominal and trans-gluteal surgery may be required. Knowledge of gluteal anatomy is also essential for transgluteal biopsy and drainages. The greater and lesser sciatic notches are noted in the posterior border of the innominate bone separated by the ischial spine. The greater sciatic foramen (GSF) is bounded antero-superiorly by the greater sciatic notch, postero-superiorly by the sacrum, and inferiorly by the sacrospinous ligament. The piriformis muscle arises from the ventral aspect of the sacrum and passes through the GSF to insert into the greater trochanter. It divides the GSF into two compartments. The suprapiriformis foramen transmits the superior gluteal vessels and nerves. The infrapiriformis foramen transmits theinferior gluteal vessels and nerves, pudendal and sciatic nerves. The lesser sciatic foramen (LSF) is bounded anteriorly by the lesser sciatic notch, superiorly by the sacrospinous ligament, and postero-inferiorly by the sacrotuberous ligament. The obturator internus tendon, the pudendal nerve, and the internal pudendal vessels pass through the LSF.

Answer 62

57. B. Wilms tumour. Sporadic aniridia is associated with nephroblastomatosis (multiple nephrogenic rests) and an increased risk of Wilms tumour. At CT, the nephrogenic rests appear as homogenous, hypodense nodules/peripheral rind, with little or no enhancement compared to the compressed normal cortical tissue. Any new, enlarging, or heterogenous mass in the setting of nephroblastomatosis indicates the development of a Wilms tumour.

Answer 63

58. A. Congenital megacalyces This is a rare developmental abnormality of the renal medulla. Imaging demonstrates dilated, multifaceted, or polygonal calyces as opposed to spherical calyces of obstructive hydronephrosis. In addition, the infundibula, renal pelvis, and ureter are normal in calibre in congenital hydronephrosis. The affected kidneys may demonstrate cortical thinning but the renal function is preserved.

Answer 64

63. B. CF. Bilateral seminal vesicle agenesis is frequently associated with bilateral agenesis of the vas deferens and mutations in the CF transmembrane conductance regulator gene (64-73%). It is thought to be related to luminal obstruction by thick secretions. Bilateral agenesis of the vas deferens is seen in 99% of CF in males. The affected patients usually have normal kidneys. Unilateral seminal vesicle agenesis and seminal vesicle cyst are commonly associated with ipsilateral renal agenesis. Bilateral calcified vas deferens is commonly seen in diabetics.

Answer 65

5 Answer A: Liver ultrasound The description is that of autosomal-recessive polycystic kidney disease. This is associated with congenital hepatic fibrosis. The less severe the renal involvement, the more severe the hepatic involvement.

Answer 66

12 Answer C: DMSA in four to six months NICE guidelines on management of UTI recommend ultrasound within six weeks and a DMSA scan at four to six months for investigation of recurrent UTI in children over three years and makes very similar recommendations for children six months to three years with recurrent UTIs.

Answer 67

13 Answer A: 1123 MIBG study with planar and SPECT images Although neuroblastoma can be detected on octreotide studies MIBG is the first line of investigation. Whole body images with I12 3 are used in the treatment & assessment of thyroid malignancy and have no place in this scenario.

Answer 68

14 Answer A: Abdominal ultrasound every three months Ten to twenty per cent of patients with Beckwith-Wiedemann syndrome develop Wilms' tumour. There is also an increased risk of developing Wilms' tumour in patients with sporadic aniridia, hemihypertrophy and genitourinary disorders such as Drash syndrome (male pseudohermaphroditism and glomerulonephritis).

Answer 69

24 Answer C: Posterior urethral valve These are congenital thick folds of mucosa within the posterior urethra. They are the most common cause of urinary tract obstruction and end-stage renal disease in boys.

Answer 70

28 Answer A: Complete ureteric duplication with infrasphincteric insertion of the upper moiety ureter In complete ureteric duplication, there is an increased risk of obstruction of the upper moiety ureter and of vesicoureteric reflux of the lower moiety ureter. The upper moiety ureter has a suprasphincteric insertion in boys, resulting in no enuresis but epididymitis and urge incontinence. In girls, the upper moiety ureter has an infrasphincteric insertion and causes both wetting in upright position & intermittent or constant dribbling of urine.

Answer 71

47 Answer C: Stage III Neuroblastoma staging: Stage I: Limited to organ of origin Stage II: Regional spread, not crossing the midline Stage III: Extending across the midline Stage IV Metastatic spread to liver, bone, brain, lung, distant lymph nodes Stage IVs: Stages I and II, with disease confined to the skin, bone marrow and liver with no radiographic evidence of skeletal metastases

Answer 72

53 Answer B: The ureter from the superior pelvis inserts below that from the inferior pelvis, and the upper renal moiety has calyceal dilatation from distal ureteric obstruction The upper moiety ureter classically inserts ectopically low, below that of the lower moiety, and it is often associated with a stenotic insertion site, which results in dilatation of the intramural ureter, forming an ectopic ureterocoele and subsequent distal ureteric obstruction. The lower moiety ureter has a more horizontal path and is more prone to reflex. RULE: Upper moiety inserts low and obstructs. Lower moiety refluxes.

Answer 73

56 Answer E: Inferior mesenteric artery The inferior mesenteric artery limits the ascent of the isthmus, and the pelves lie anteriorly. Renal calculi are more common. Risk of TCC (transitional cell carcinoma) is three to four times the general population. Incidence of horseshoe kidney is 1-4:1000.

Answer 74

66 Answer B: Multiple cysts of varying sizes, an absent renal pelvis and dysplastic renal parenchyma Calcifications may be seen in the cyst walls or in the septations between the cysts. The contralateral kidney often shows compensatory hypertrophy.

Answer 75

67 Answer B: Multicystic dysplastic kidney Multicystic dysplastic kidney is a congenital, non-hereditary renal dysplasia in which there is no functioning renal tissue, instead multiple thin-walled cysts and connective tissue. If bilateral it is fatal at birth.

Answer 76

6 Answer D: Noonan's syndrome Noonan's $ has a phenotype similar to Turner's syndrome but with a normal karyotype. It occurs in both sexes.

Answer 77

7 Answer E: Involvement of the IVC Regional lymph nodes are removed at surgery. Caval involvement is an indicator of unresectability

Answer 78

6 Answer C: Heterogeneous solid mass with low density areas and calcifications displacing the right kidney and encasing the IVC These findings are typical for neuroblastoma, which contains calcifications on CT in 85%, can extend across the midline and encases rather than invades vascular structures. Option (a) describes a rhabdoid tumour of the kidney, option (b) mesoblastic nephroma (although 90% of these occur before 1 year), option (d) Wilms' tumour and option (e) adrenal haemorrhage.

Answer 79

10 Answer B: Renal tract ultrasound Prune belly syndrome is a congenital non-hereditary disorder that almost exclusively affects males. It is a triad of abdominal wall muscle insufficiency, nonobstructed distended ureters (+/hydronephrosis and a degree of renal dysplasia) and bilateral undistended testes.

Answer 80

22 Answer B: Multicystic dysplastic kidney Multicystic dysplastic kidney is the second most common cause of an abdominal mass in a neonate after hydronephrosis. The unilateral form is more common on the left and is associated with anomalies of the contralateral kidney. The bilateral form is fatal.

Answer 81

33 Answer D: Wilms' tumour Wilms' tumour is the most common malignant abdominal neoplasm in one to four year olds. Ninety per cent of cases present with a painless abdominal mass. The Rule of I0s applies to Wilms' tumours: * 10% unfavourable histology * 10% bilateral * 10% vascular invasion * 10% calcification * 10% pulmonary metastases at presentation.

Answer 82

42 Answer B: DMSA four to six months after the acute infection NICE guidelines refer to age group, recurrent, typical or atypical infections and the investigations vary accordingly. A retrograde study should never be performed during an infection.

Answer 83

43 Answer B: Simple ureterocoele This is the typical `cobra head' or `spring onion' appearance on IVP with a radiolucent halo formed by the ureteral wall and adjacent bladder urothelium. A simple ureterocoele is usually an incidental finding in adults; M:F = 2:3. It may be bilateral (33%). An ectopic ureterocoele is usually seen in the upper moiety ureter of a duplex kidney (80%). Twenty per cent of ectopic ureterocoeles are seen in a single non-duplicated system and are usually associated with a small/ poorly functioning, sometimes non-visualised ipsilateral kidney (the further the ureteral orifice is from the normal site of insertion, the more dysplastic the kidney tends to be). (c), (d) and (e) are causes of pseudoureterocoele. No protrusion of the ureter is seen into the bladder lumen.

Answer 84

49 Answer D. Mesoblastic nephroma Mesoblastic nephroma is the commonest solid renal mass in a neonate; 90% occur in the first year. It is derived from early nephrogenic mesenchyma and can have a variable appearance on US. Distinguishing features are lack of a well-defined cleavage plane, lack of extension into renal vein (cf. Wilms') or pelvis (cf. multilocular cystic nephroma). Sarcomatous transformation and metastases are rare. Treatment is nephrectomy with an excellent prognosis.

Answer 85

56 Answer D: Hepatic fibrosis ARPKD is classified into four subgroups corresponding to the age of onset: perinatal, neonatal, infantile and juvenile. The abnormality lies with the epithelium of the collecting ducts resulting in ductal proliferation and dilatation. The proportion of ducts involved affects the degree of renal impairment and age of onset. Those in the juvenile group have the lowest number of ducts affected, but the degree of hepatic fibrosis is greatest in this group and death occurs from portal hypertension.

Answer 86

53 Answer D: Grade IV vesicoureteric reflux

Answer 87

61 Answer C: Umbilical-urachal sinus The urachus is an embryological remnant of the cloaca and the allantois, and usually closes to become the median umbilical ligament. There are four types of urachal remnant. (1) Patent urachus (continuous connection between the umbilicus and bladder), usually symptomatic and diagnosed in the neonatal period. (2) Umbilical-urachal sinus is a blind dilatation of the urachus at the umbilical end. A small opening into the umbilicus is usually present and trauma from the piercing has opened it up. (3) Vesico-urachal diverticulum is a communication only with the bladder dome. (4) Urachal cyst consists of closure at both ends with isolated dilatation usually in lower third. Meckel's diverticulum is the remnant of the vitello-intestinal duct.

Answer 88

66 Answer C: Haemolytic uraemic syndrome This is commonly caused by E. coli infection and is the most common cause of acute renal failure in children requiring dialysis. The classic triad is microangiopathic haemolytic anaemia, thrombocytopaenia and acute oliguric renal failure leading to uraemia.

Answer 89

1 Answer B: Heterogeneous suprarenal mass containing calcification displacing the left kidney The findings are those of a primary adrenal neuroblastoma with multiple metastatic skin lesions, so called Blueberry Muffin syndrome. Thirty-six per cent of neuroblastomas arise in the adrenals and are almost always unilateral. Common sites of metastases in decreasing order of occurrence are: bone, regional lymph nodes, orbits, liver, brain and lung.

Answer 90

4 Answer B: Renal vein thrombosis Risk factors for renal vein thrombosis in neonates include advanced maternal age, diarrhoea, sepsis, birth trauma, adrenal haemorrhage and dehydration from vomiting. It is more common on the left due to the longer left RV.

Answer 91

20 Answer A: Ultrasound during the acute infection, DMSA four to six months after the acute infection and MCUG An atypical infection includes septicaemia and failure to respond to appropriate antibiotics within 48 hours

Answer 92

29 Answer A: Differential function can be measured Differential function can be measured and assessment of split function in duplex systems can be made. A horseshoe kidney may be demonstrated but it is not a primary indication for a DMSA. GFR is an entirely different study using Tc-99m- labelled DTPA and serial blood tests. No dynamic images are obtained on DMSA and obstruction or reflux of urinary flow is not a feature. However, the sequelae of infection, such as cortical scarring and reduced differential function, can be accurately demonstrated.

Answer 93

35 Answer B: First year of life Sixty-five per cent first year, 23% 1-16 years, 8% prenatal, diagnosis by urethrogram

Answer 94

41 Answer B: Turner's syndrome Turner's syndrome is a monosomy 45, XO. It is associated with renal ectopia and horseshoe kidney. Neonates with Turner's may be born with lymphoedema of the hands and feet.

Answer 95

50 Answer B: Cystic partially differentiated nephroblastoma Cystic partially differentiated nephroblastoma (CPDN) and cystic nephroma make up the two forms of multilocular cystic renal tumour (MDCT). They originate from metanephric blastema and have identical imaging features. CPDN is typically seen in boys aged three months to four years (90% <2 years) and blastemal cells are present histologically. Cystic nephroma is seen typically in adult women aged 40-60 years, and no septal blastemal cells are present. Cystic mesoblastic nephroma is rare after the age of six months (commonest neonatal renal mass), and renal cell carcinoma is uncommon under the age of two years. Wilms' tumour is the commonest malignant abdominal tumour in children aged one to eight years, and the third most common cause of all renal masses in childhood (after hydronephrosis and multicystic dysplastic kidney).

Answer 96

60 Answer A: Early filling images Early filling during VCUG is essential as bladder tumours or a ureterocoele may be missed when the bladder is full. A single AP image will suffice. During voiding steep oblique views are necessary to visualise the VUJ. AP voiding images increase gonadal radiation dose.

Answer 97

70 Answer: C: Posterior urethral valves Posterior urethral valves are the most common cause of bilateral hydronephrosis in a male infant. There are three types described of which type I is the most common and represents vestiges of the Wolffian duct extending anteroinferiorly

Answer 98

17. (e) Multicystic dysplastic kidney The sonographic appearances of this condition are typical, showing noncommunicating cysts of varying sizes separated by hyperechoic renal parenchyma (differentiating it from hydronephrosis). Autosomal dominant polycystic kidney disease is seen in adults. Autosomal recessive polycystic kidney disease shows bilateral gross renal enlargement with hyperechoic kidney involvement and usually no cysts are seen on ultrasound.

Answer 99

23. (d) Congenital pelvic–ureteric junction obstruction Findings of the MAG-3 scan along with typical imaging demonstrating obstruction at the pelviureteric junction.

Answer 100

23. (d) Vesicoureteral reflux usually present With an abnormal urinary tract, there may be failure of fetal micturition and thus oligohydramnios. This is seen exclusively in men and reflux is present in the majority of cases. The bladder neck is typically wide with a tapering dilatation of the posterior urethra.

Answer 101

30. (b) Posterior urethral valves There are congenital folds of mucous membrane located in the posterior urethra. The findings on micturating cystourethrogram are characteristic with fusiform distension and elongation of posterior urethra, vesicoureteral reflux (usually to the left), diminution of urethral calibre and hypertrophy of bladder neck with trabeculations.

Answer 102

31. (a) Neuroblastoma A childhood suprarenal mass with calcification, crossing the midline to encase the inferior vena cava and aorta is almost certainly a neuroblastoma.

Answer 103

31. (b) Nephroblastoma Also called Wilms’ tumour, this lesion typically presents as a large mass, crossing the midline and commonly displacing the large vessels (in contrast to neuroblastoma, where the mass encases the vessels). This is the most common neoplasm in children between 1 and 8 years of age.

Answer 104

41. (c) Sacrococcygeal germ cell tumour These are relatively rare tumours and can be benign or malignant. Calcification is seen on CT in more than half of cases, more frequently in benign lesions. Direct invasion of surrounding structures suggest malignancy. Ovarian teratoma, neuroblastoma and gastrointestinal duplication cysts are all rare and do not (usually) extend around the sacrum. Meningoceles are cystic structures.

Answer 105

43. (a) Autosomal recessive polycystic kidney disease This condition can be diagnosed as early as 17–18 weeks on obstetric ultrasound. The kidneys may be massively enlarged measuring up to 10–20 times normal size with an enlarged renal: abdominal circumference ratio of > 0.30. The renal parenchyma is hyperechoic and there may be oligohydramnios. There is an association with congenital hepatic fbrosis.

Answer 106

44. (b) Mesoblastic nephroma This is a hamartoma and is the most common solid neoplasm in neonates. It typically involves the renal sinus and there is no invasion of the veins (differentiating it from Wilms’ tumour) or the collecting system.

Answer 107

45. (b) Grade II Grade I is reflux only in the ureter and not into the pelvicalyceal system. Grade III is reflux into the pelvicalyceal system with mild dilatation of the ureter and pelvicalyceal system. Grade IV and V are more severe dilatations and tortuosity of the ureter and pelvicalyceal system.

Answer 108

46. (e) Non-hereditary multisystem disorder Prune belly syndrome is a congenital non-hereditary multisystem disorder, almost exclusive to men (M:F = 19:1). A triad of abdominal wall deficiency, non-obstructed dilated redundant ureters and bilateral undescended testes is seen

Answer 109

Answers: (a) Not correct (b) Correct (c) Correct (d) Correct (e) Not correct Explanation: Antenatal ultrasound shows multiple non-communicating cysts of variable size. Serial ultrasound scans of multicystic dysplastic kidney show renal involution. Nephrectomy is required if it fails to involute or if there is uncontrolled hypertension. Multicystic dysplastic kidney is the second most common cause of neonatal abdominal mass (first is hydronephrosis).

Answer 110

Answers: (a) Correct (b) Correct (c) Correct (d) Correct (e) Correct Explanation: Ureterocoele is a congenital dilatation of distal most portion of ureter. In minority of cases it is an isolated finding and seen in adults. On IVP it shows ‘cobra head’ sign. Complications include obstructive cystic renal dysplasia.

Answer 111

Answers: (a) Not correct (b) Not correct (c) Not correct (d) Correct (e) Not correct Explanation: Prune belly syndrome is a sporadic nonhereditary condition, exclusively affecting males. It is characterized by triad of absent anterior abdominal wall muscles, non-obstructed megaureters and cryptorchidism (due to bladder distension). In 20% cases death occurs in first month of life and another 30% within 2 yrs of life. Mild cases survive into adulthood.

Answer 112

Answers: (a) Not correct (b) Not correct (c) Not correct (d) Correct (e) Not correct Explanation: Infantile polycystic kidney disease is inherited in an autosomal recessive pattern with antenatal form being the most common type. This type presents in utero and progresses to renal failure and pulmonary hypoplasia (Potter sequence) with majority of patients dying within 24 hrs of life. The milder forms are neonatal, infantile and juvenile presenting in the first few years of life. They are associated with more severe hepatic fibrosis and less severity of renal disease. The affected kidneys are replaced my multiple small elongated cysts representing dilated tubules and collecting ducts. The cysts are too small to be delineated on ultrasound, thus producing an echogenic pattern due to multiple interfaces. There is poor corticomedullary differentiation. Adult type polycystic disease shows autosomal dominant inheritance with defects on chromosome 16 and 4.

Answer 113

Answers: (a) Correct (b) Not correct (c) Correct (d) Correct (e) Correct Explanation: Ureterocoeles which are related to the upper pole moiety of a duplex kidney occur 8 times more frequently in girls than boys. Ureterocoeles related to non-duplicated system show an equal gender incidence.

Answer 114

Answers: (a) Not correct. (b) Not correct (c) Not correct (d) Correct (e) Correct Explanation: Hematocolpos refers to vagina distended with blood and hematometra refers to uterine cavity distended with blood. An imperforate hymen is the most common cause of hematocolpos. Approximately 25% of neonates have a fluid collection within the endometrial cavity, thus a normal finding.

Answer 115

Answers: (a) Not correct (b) Not correct (c) Correct (d) Correct (e) Correct Explanation: Peak age of Wilm’s tumor is 3 years and neuroblastoma is most common in children below 2 years. Stippled type of calcification is seen in 85% of cases of neuroblastoma. Calcification is uncommon in Wilm’s and is seen as curvilinear or amorphous type in 15% cases.

Answer 116

Answers: (a) Not correct (b) Correct (c) Not correct (d) Not correct (e) Not correct Explanation: Hydronephrotic kidney is the most common abdominal mass in neonates. Mesoblastic nephroma is associated with polyhydramnios and thus premature labor. It cannot be distinguished from Wilm’s tumor on cross-sectional imaging. It is benign and does not invade venous structures, hence differentiating it from Wilm’s tumor.

Answer 117

Answers: (a) Correct (b) Correct (c) Correct (d) Not correct (e) Not correct Explanation: Multicystic dysplastic kidney shows non-communicating cysts with no normal renal parenchyma.

Pediatric GU Flashcards

(141 cards)