Urological pathology Flashcards
Features of kidney stones
• Form in the renal collecting ducts and can be deposited anywhere in tract
• M:F 3:1 incidence
• Common points of impaction are pelvi-ureteric junction, pelvic brim, vesico-ureteric junction
• Management
o Small stones may pass spontaneously
o Large stones may be removed by endoscopic or percutaneous methods or using
lithotripsy
Main types of kidney stone
o Calcium Oxalate 75%
§ Too much calcium absorption from the gut
§ Intrinsic renal problems – impaired calcium absorption from proximal tubule
o Magnesium Ammonium Phosphate 15%
§ Triple stones
§ Commonly due to urease producing organisms which alkanise urine
promoting precipitation of magnesium ammonium phosphate salts
§ Often form “staghorn calculi” – very large and painful
o Uric Acid – 5%
§ In patients with hyperuricaemia (gout/rapid cell turnover)
Features of benign prostatic hyperplasia
• Dihydrotestosterone-mediated hyperplasia of prostatic stromal and epithelial cells,
resulting in the formation of large nodules.
• Nodule formation compresses prostatic urethra leading to outflow tract obstruction
• Symptoms: difficulty urinating, retention, frequency, nocturia, overflow dribbling.
• Histology – nodule formation, prostatic epithelial ducts with duct spaces
• Treatment: TURP, 5α reductase inhibitors.
Features of prostate cancer
- Adenocarcinoma is the commonest form in men over 50y.
- Arises from precursor lesion PIN (prostatic intraepithelial neoplasia)
- Risk factors: age, race, family history, and hormonal and environmental influences.
- Classically arises in peripheral zone of gland, and neoplastic tissue is firm.
- Local spread to the bladder and haematogenous spread to bone.
- Grading: Gleason system, based on degree of differentiation and glandular patterns.
- Diagnosis: History, examination, PSA (over 4ng/ml is indicative)
Features of testicular tumours
Most testicular tumours are germ cell tumours – arising from germ cells in the testes. Commonly
seen in men aged 20-45.
Maldescent of testis- In 1% of males, 90-95% in inguinal canal à 10x increase in Testicular Ca
• Most arise from a precursor lesion - intratubular germ cell neoplasia
• Seminoma: most common type of germinal tumour. Peak age: 30s. Radiosensitive.
• Teratoma: occur at any age from infancy to adult life. Regarded as malignant when occurs
in the post-pubertal male. Chemosensitive. Biologic markers for germ cell tumours: AFP,
HCG, and LDH
• Embryonal carcinoma – resembles embryonic tissue
• Yolk sac tumour
• Choriocarcinoma
Germ cell vs non-germ cell tumours
Germ cell - 95% Seminoma, spermatocytic seminoma, embryonal carcinoma, yolk sac tumour, choriocarcinoma, teratoma Cryptorchidism, testicular dysgenesis, genetic factors e.g. Kleinfelters, testicular feminisation
Non-germ cell - 5%
Leydig cell tumour (derived from
stroma), Sertoli cell tumour
(derived from sex cord)
Types and features of benign renal tumours
Papilliary adenoma Epithelial - Bland epithelial cells growing in a papilliary or tubopapilliary pattern Well circumscribed cortical nodules
Oncocytoma Epithelial Macroscopic – mahogany brown Microscopic – sheets of cells, pink cytoplasm, form a nest of cells
Angiomyolipoma
Mesenchymal - Fat spaces, thick bloods
vessels and spindle cell
components
Types of malignant renal tumours
Renal cell carcinoma
Nephroblastoma
Transitional cell carcinoma
Features of renal cell carcinoma
Most common – epithelial tumour
RFs – smoking, HTN, obesity, long-term dialysis
• Clear Cell (70%) Macroscopic – golden yellow with haemorrhagic areas Microscopic – nests of epithelium with clear cytoplasm
• Papillary (15%)
Macroscopic – friable brown tumour
Microscopic – papilliary/
tubopapilliary growth pattern >5mm
• Chromophobe (5%)
Macroscopic – solid brown tumour
Microscopic – sheets of large cells,
distinct cell borders
Features of nephroblastoma
Childhood renal
neoplasm
2nd most common
childhood malignancy
Microscopic – 1. Small round blue cells (very undifferentiated) 2. Epithelial component – cells trying to differentiate and form primitive renal tubules
Features of transitional cell carcinoma
Epithelial neoplasm arising from the urothelial tract (anywhere from renal pelvis, ureter, bladder, urethra) Most commonly in the bladder
• Non-invasive papillary urothelial carcinoma Frond like growths projecting from bladder wall, often multifocal Microscopic – papilliary fronds lined by urothelium Can either be low grade or high grade • Invasive urothelial carcinoma Tumour with invasive behaviour. Usually grow as solid masses, fixed to tissue
Features and types of bladder tumours
Transitional Cell (Urothelial) Tumours 90% of all bladder tumours. Male: female = 3:1, and 80% occur between 50-80 years
Squamous Cell Carcinoma: more frequent in countries with endemic urinary
schistosomiasis
Adenocarcinoma: rare, arising from extensive intestinal metaplasia or from urachal remnant
