4.2 Ureter, Bladder, Urethra

Question 1

Ureteric development

Answer 1

From ureteric bud (if >1 bud, can have ureteric duplication), arising from mesonephric duct; 10-25 calyces/kidney
Weigert-Meyer: Upper moiety ureter inserts inferomedial to lower moiety
Thus upper moiety can develop ureterocoele (cobra head on IVP; can project into bladder and obstruct other ureter), lower moiety develops reflux
Upper moiety may have extravesical insertion - typically bladder neck, urethra or vagina / seminal vesicles, vas deferens
Ectopic ureter F/M = 6/1; causes UTIs, obstruction, incontinence

Question 2

Retrocaval ureter

Answer 2

Ureter passes behind IVC and exits between aorta and IVC

Medial looping at L2/L3 on IVP, can cause ureteral narrowing

Question 3

Ovarian vein syndrome

Answer 3

Right gonadal vein crosses ureter and drains into IVC, left gonadal vein drains to left renal vein
Ureteral notching / dilatation / obstruction due to ovarian vein thrombosis / varices
Associated with pregnancy

Question 4

Retroperitoneal fibrosis

Answer 4

Idiopathic form (two thirds) = Ormond’s Disease (M>F)
Originates just inferolateral to aortic bifurcation and extends superiorly, but limited anteriorly by peritoneum
Typically involves left ureter before right, usually at L3-L5 level
Associations - IBD, PSC, fibrosing mediastinitis, Riedel’s thyroiditis, sclerosing mesenteritis, orbital pseudotumour
Imaging - Soft tissue layered around aorta and IVC, loss of peristalsis in involved ureteric segment (but always spares ureteric mucosa), does not extend between aorta and vertebrae (unlike malignant lymphadenopathy)
Early or malignant RPF - high T2W; mature fibrotic plaque - low T2W
Renal impairment out of proportion with degree of hydronephrosis, but stenting usually easy

Question 5

Causes and Sequelae of RPF

Answer 5

Causes:
AAA
RP metastases (lymphoma, breast, carcinoid) - Desmoplastic reaction: HD > NHL > anaplastic & metastases
RP haematoma
RP abscess (diverticular, appendix)
Urinoma
Drugs (hydralazine, methylsergide, methyldopa, ergot)
Radiation

Sequelae:
Lower extremity / scrotal oedema
DVT

Question 6

Retroperitoneal tumours

Answer 6

90 % malignant, usually > 10 cm at diagnosis

Mesodermal
Liposarcoma (usually myxoid or pleomorphic; little fat on CT)
Leiomyosarcoma (large heterogenously enhancing mass, central necrosis)
Fibrosarcoma
Lymphoma, others

Neural
Neurofibroma
Neuroblastoma
Phaeochromocytoma

Embryonic
Teratoma
Primary germ cell tumour

Question 7

Pelvic lipomatosis

Answer 7

True pelvis infiltrated by unencapsulated mature adipose tissue
Two thirds of cases are black males
Causes UTIs / obstruction, constipation
Associations: cystitis glandularis (75%, form of proliferative cystitis), increased risk bladder adenocarcinoma
‘Inverted pear’ shaped bladder, reduced bladder capacity, medial deviation of ureters
Enlarged retrorectal space on Ba enema

Question 8

Ureteritis cystica

Answer 8

Sterile submucosal fluid collections due to intramural inflammation, causing encystment and submucosal extension of transitional epithelium; not premalignant
Usually unilateral, multicentric, smooth, round filling defects on IVU (most 2-4 mm diameter)
Associated with chronic UTIs

Question 9

Ureteral Psuedodiverticulosis

Answer 9

Outpouchings 1-2 mm of epithelium into lamina propria, associated with inflammation
50% develop uroepithelial malignancy

Question 10

Ureteric trauma

Answer 10

Usually penetrating injury causing urinoma / discontinuity / extravasation
Avulsion usually at PUJ due to deceleration (commonest in children)

Question 11

Malakoplakia

Answer 11

Yellow subepithelial plaques of mononuclear histiocytes containing Michaelis-Gutmann bodies
Cobblestone appearance on IVP, most common in bladder
F>M, usually diabetic or immunocompromised, strong association with E Coli UTIs
Causes LUTs and haematuria; rarely invades bone

Question 12

Ureteric tumours

Answer 12

50% develop bladder cancer, 75% unilateral, 5% bladder cancer patients develop ureteric cancer
Malignant:
Epithelial - TCC, SCC, adenocarcinoma;
Mesodermal - Sarcoma, angiosarcoma, carcinosarcoma
Benign:
Epithelial - inverted papilloma, polyp, adenoma
Mesodermal - fibroma, haemoangioma, myoma, lymphangioma
Goblet sign: retrograde pyelogram with dilated ureteral segment distal to obstruction, with filling defect and mensicus
Metastatic sites of ureteric primaries: RP LNs (75%) > liver, lung (60%) > bone (40%) > GIT (20%)

Question 13

Bacterial cystitis

Answer 13

E Coli > Staph > Strep > Psuedomonas
Mucosal thickening (cobblestone), stranding perivesical fat
Emphysematous cystitis usually E Coli in DM, neurogenic bladder (S2-S4 dermatome; UMN lesion = spastic, LMN lesion = atonic) or outlet obstruction (intramural gas, air/fluid level in bladder)

Question 14

Cystitis cystica and glandularis

Answer 14

Cystica - mulitple serous fluid filled cysts
Glandularis - mucin-secreting glandular hypertrophy
Chronic reactive inflammation, causes LUTs; muscle layer is intact; both can coexist with GU TB
Filling defects on urography with hypervascular polypoid mass on CT & MR
Low T1W, low signal with central branching high signal on T2W

Question 15

Miscellaneous causes of cystitis

Answer 15

Radiation: approximately 15% of patients receiving pelvic irradiation
Cyclophosphamide: 40% develop haemorrhagic cystitis
Eosinophilic: Allergic reactions

Question 16

Schistosomiasis

Answer 16

Association with bladder SCC, foreign body reaction in mucosa, M>F. DDx = TB
Bladder becomes fibrotic but remains distensible and normal volume.
Inflammatory pseudopolyps = bilharzomas
XR: Bladder wall (initally anterior at base, then encircles) and distal ureteric calcification (parallel / linear)
IVU: Ureteritis cystica, ureteric dilatation / strictures

Question 17

Inflammatory pseudotumour

Answer 17

Non-neoplastic proliferation of myofibroblastic spindle cells and inflammatory cells with myxoid components
Symptoms: Haematuria, iron deficiency anaemia, fever
Single exophytic / polypoid bladder mass ± ulceration (but solid and cystic variants); spares trigone, can extend extravesically
Enhances post contrast on CT and MR, can have internal flow on US

Question 18

Endometriosis

Answer 18

Bladder commonest site of urinary tract involvement (1-5% of endometriosis, premenopausal only), cyclic haematuria in 20%
Usually posterior wall above trigone or dome, may be inseparable from anterior wall of uterus, tends to be deeply infiltrating
High signal T1W ± high signal T2W ± homogeneous or peripheral contrast enhancement

Question 19

Nephrogenic adenoma

Answer 19

Benign reactive process to chronic irritation involving lamina propria but not muscle, not premalignant
63% recurrence post resection

Question 20

Bladder malignancy

Answer 20

4% of all cancers, M/F = 3/1, 50-60 y/o
TCC (90%) - aniline dye, phenacetin, radiation, tobacco, interstitial nephritis
SCC (5%) - calculi, chronic infection, schistosomiasis
Adenocarcinoma (2%) - bladder exstrophy, urachal remnant, cystitis glandularis (10% pass mucus PU)
95% carcinomas; leiomyosarcoma is commonest non-epithelial malignancy
Metastases to bladder: stomach, breast
Urachal carcinoma (0.4% bladder cancer, 40% bladder adenocarcinomas) - 70% calcified, 70% occur before 20 y/o

Question 21

Staging bladder cancer

Answer 21

T1: Mucosa and submucosa
T2: Superficial muscle layer
T3a: Deep muscle layer
T3b: perivesical fat
T4: other organs

Question 22

Leukoplakia

Answer 22

Squamous metaplasia of transitional epithelium (keratinisation), uncertain if premalignant; 30% have haematuria
Associations: chronic infection (80%), calculi (40%)

Question 23

Bladder trauma

Answer 23

Extraperitoneal rupture (Pelvic fractures) - conservative management
Usually occurs anterolateral at bladder base
Causes pear shaped bladder
Intraperitoneal rupture (Blunt trauma, stab wounds) - surgical treatment
Usually occurs bladder dome
Contrast collects in paracolic gutters

Question 24

Urethral injuries

Answer 24

Type 1: Intact urethra, stretched and narrowed by periurethral haematoma
Type 2: Rupture above urogenital diaphragm; extraperitoneal contrast
Type 3: Rupture below urogenital diaphragm; contrast in extraperitoneal space and perineum

Question 25

Urethral strictures - causes

Answer 25

Gonococcal (commonest in USA, 40%) - usually bulbopenile urethra
TB - ‘watering can’ perimeum
Condylomata acuminata - HPV infection, papillary filling defects
Trauma - instrumentation, catheters (usually penoscrotal junction)
Tumors (SCC 80%, TCC 15%; prostate cancer)

Question 26

Female urethra, diverticulum and carcinoma

Answer 26

Female urethra ≤ 4 cm long
Diverticula usually due to obstruction of Skene’s glands
Carcinoma - F/M = 5/1, 70% SCC, 90% in distal two thirds