32 Urinary diseases 2 Flashcards
Name the four methods of urinary tract compression with examples.
Lumen obstruction: tumour, stricture, urinary calculi.
Wall abnormalities: congenital, tumour.
External compression: pregnancy, tumour, inflammation (retroperitoneal fibrosis).
Functional: reflux, neurological conditions.
What are the sequelae of urinary tract obstruction?
Infection: cystitis, ascending pyelonephritis.
Stone/ calculi formation.
Kidney injury.
What does acute complete obstruction uropathy cause?
Mild dilatation and cortical atrophy. OR.
Reduction in GFR and acute renal failure.
How does intermittent uropathy obstruction cause cortical atrophy?
Filtrate passes back into interstitium, compressing medulla and reducing its concentrating power. OR.
Continued glomerular filtration and dilation of cortices and calyces.
What are the clinical features of acute complete urinary tract obstruction?
Pain.
Acute renal failure and anuria.
What are the clinical features of bilateral partial urinary tract obstruction?
Initially polyuric with progressive renal scarring and impairment.
Who characteristically gets renal calculi?
20-30 years.
Male.
What is the pathogenesis of renal calculi? (4)
Increase in substances which may precipitate.
Change in constituents causing precipitation.
Poor urine output - supersaturation.
Decreased citrate levels.
What % of renal stones are calcium based?
What causes calcium based renal stones? (3)
70%.
Hypercalciuria: hypercalcaemia, increased intestinal absorption, decreased tubular absorption.
Gout.
Hyperoxaluria.
How do struvite renal calculi form?
Urease producing bacterial infection (Protease) converts urea to ammonia, raising the pH. Causes precipitation of magnesium ammonium phosphate salts and formation of staghorn calculi.
What are the causes of urate stones?
Hyperuricaemia due to gout or high cell turnover (leukaemia).
What is the cause of cysteine stones?
Rare causes where kidney cannot reabsorb amino acids.
What are the sequelae of renal calculi? (4)
Obstruction.
Haematuria.
Infection.
Squamous cell metaplasia ± carcinoma.
What are the risk factors for renal carcinoma? (6)
Tobacco. Obesity. Hypertension. Oestrogens. Acquired cystic kidney disease. Asbestos exposure.
What is the most common type of renal cell carcinoma?
Clear cell.
What is Von-Hippel-Lindau syndrome?
Tumours? (3)
VHL gene required for the breakdown of Hypoxia Inducible Factor 1 (HIF1 - an oncogene). Mutation leads to cell growth and survival.
Tumours develop in kidneys, blood vessels and pancreas.
How does renal cell carcinoma present? (4)
Hameaturia, palpable abdominal mass, costovertebral pain.
25% with systemic symptoms/metastasis.
What are the paraneoplastic syndromes associated with renal cell carcinoma? (3).
Cushing’s (ACTH).
Hypercalcaemia (Parathyroid hormone related peptide).
Polycythaemia (erythropoietin).
Name two rare types of renal cell carcinoma?
Papillary.
Chromophobe.
What is the morphology of clear cell renal carcinoma?
Microscopy? (4)
Well defined yellow tumour with haemorrhage areas.
Clear cells, delicate vasculature, small and pale nuclei.
What is the morphology of papillary renal carcinoma?
Microscopy? (3)
Cystic and multiple tumours.
Cuboidal, foamy cells with surrounding fibrovascular cores with macrophages.
What is urothelial (transitional) cell carcinoma and where may it arise?
Arises from specialised multilayered epithelium.
Most common in bladder, but anywhere from renal pelvis to urethra.
What are the risk factors for urothelial (transitional) cell carcinoma? (6)
Age.
M > F.
Carcinogens: smoking, arylamines, cyclophosphamide, radiotherapy.
How does urothelial (transitional) cell carcinoma commonly present? (4)
Haematuria - most common.
Urinary frequency.
Pain on urination.
Urinary tract obstruction.
