Obstructive Uropathy and Urological Tumours

Obstructive Uropathy

•    Definition: Blockage of urine flow at any level of the urinary tract → back pressure, hydronephrosis, renal dysfunction.

•    Causes:

o    Intraluminal: renal/ureteric calculi, sloughed papilla

o    Intramural: ureteric strictures, urethral valves/strictures

o    Extrinsic compression:

    Men: BPH, prostate cancer

    Women: pelvic tumours (e.g. ovarian, uterine)

    Retroperitoneal masses, fibrosis

•    Clinical Features:

o    Flank pain, anuria/oliguria (acute obstruction)

o    Palpable bladder, lower abdominal discomfort

o    Post-renal AKI if bilateral or in a solitary kidney

•    Investigations:

o    Bladder scan: assess post-void residual volume

o    Renal ultrasound: hydronephrosis, renal size

o    CT KUB: helpful if stone suspected

o    Urethroscopy/cystoscopy: in urethral/prostatic obstruction

•    Management:

o    Relieve obstruction:

    Catheterisation (urethral or suprapubic)

    Nephrostomy for upper tract obstruction

o    Treat underlying cause

Retroperitoneal Fibrosis

•    Definition: Fibrotic tissue encases ureters → obstruction

•    Causes:

o    Idiopathic (most common)

o    Secondary: malignancy (e.g. lymphoma), drugs (e.g. methysergide, ergotamines), infections

•    Clinical Features:

o    Flank/back pain, weight loss

o    Renal impairment (bilateral ureteric obstruction)

•    Diagnosis:

o    CT or MRI: retroperitoneal mass around aorta/ureters

o    Elevated inflammatory markers (ESR, CRP)

•    Management:

o    Corticosteroids ± immunosuppression

o    Stenting or nephrostomy if significant obstruction

Renal Cell Carcinoma (RCC)

•    Origin: Arises from renal tubular epithelium

•    Clinical Triad (classic, but uncommon):

o    Haematuria

o    Flank mass

o    Flank pain

•    Other features:

o    Paraneoplastic syndromes:

    ↑ EPO → polycythaemia

    ↑ PTHrP → hypercalcaemia

    ↑ renin → hypertension

    Stauffer’s syndrome: non-metastatic hepatic dysfunction

•    Diagnosis:

o    CT abdomen: gold standard for staging

o    Ultrasound: initial detection

o    CXR/CT chest: to exclude lung metastases

•    Management:

o    Radical nephrectomy if localised

o    Immunotherapy (e.g. checkpoint inhibitors) for advanced disease

o    RCC is resistant to chemotherapy and radiotherapy

Urothelial Carcinoma (Transitional Cell Carcinoma)

•    Location: Renal pelvis, ureters, bladder (most common in bladder)

•    Risk factors:

o    Smoking (most important)

o    Exposure to aniline dyes, cyclophosphamide, radiation

•    Clinical Features:

o    Painless macroscopic haematuria (key feature)

o    Irritative voiding symptoms (frequency, urgency)

•    Diagnosis:

o    Cystoscopy + biopsy

o    Urine cytology, CT urogram for upper tract

•    Management:

o    Non-muscle invasive: TURBT + intravesical BCG/mitomycin C

o    Muscle invasive: radical cystectomy ± chemo/radiotherapy

Wilms Tumour (Nephroblastoma)

•    Epidemiology: Most common renal tumour in children (typically <5 years)

•    Genetics: Associated with WT1 mutation (chromosome 11), WAGR syndrome (Wilms, Aniridia, Genitourinary malformation, Retardation)

•    Clinical Features:

o    Painless abdominal mass

o    Haematuria, hypertension, fever

o    Often detected incidentally

•    Diagnosis:

o    Ultrasound or CT scan of abdomen

o    CXR to check for lung metastases

•    Management:

o    Nephrectomy + chemotherapy

o    Excellent prognosis if localised