32 Urinary diseases 2

Question 1

Name the four methods of urinary tract compression with examples.

Answer 1

Lumen obstruction: tumour, stricture, urinary calculi.
Wall abnormalities: congenital, tumour.
External compression: pregnancy, tumour, inflammation (retroperitoneal fibrosis).
Functional: reflux, neurological conditions.

Question 2

What are the sequelae of urinary tract obstruction?

Answer 2

Infection: cystitis, ascending pyelonephritis.
Stone/ calculi formation.
Kidney injury.

Question 3

What does acute complete obstruction uropathy cause?

Answer 3

Mild dilatation and cortical atrophy. OR.

Reduction in GFR and acute renal failure.

Question 4

How does intermittent uropathy obstruction cause cortical atrophy?

Answer 4

Filtrate passes back into interstitium, compressing medulla and reducing its concentrating power. OR.
Continued glomerular filtration and dilation of cortices and calyces.

Question 5

What are the clinical features of acute complete urinary tract obstruction?

Answer 5

Pain.

Acute renal failure and anuria.

Question 6

What are the clinical features of bilateral partial urinary tract obstruction?

Answer 6

Initially polyuric with progressive renal scarring and impairment.

Question 7

Who characteristically gets renal calculi?

Answer 7

20-30 years.

Male.

Question 8

What is the pathogenesis of renal calculi? (4)

Answer 8

Increase in substances which may precipitate.
Change in constituents causing precipitation.
Poor urine output - supersaturation.
Decreased citrate levels.

Question 9

What % of renal stones are calcium based?

What causes calcium based renal stones? (3)

Answer 9

70%.
Hypercalciuria: hypercalcaemia, increased intestinal absorption, decreased tubular absorption.
Gout.
Hyperoxaluria.

Question 10

How do struvite renal calculi form?

Answer 10

Urease producing bacterial infection (Protease) converts urea to ammonia, raising the pH. Causes precipitation of magnesium ammonium phosphate salts and formation of staghorn calculi.

Question 11

What are the causes of urate stones?

Answer 11

Hyperuricaemia due to gout or high cell turnover (leukaemia).

Question 12

What is the cause of cysteine stones?

Answer 12

Rare causes where kidney cannot reabsorb amino acids.

Question 13

What are the sequelae of renal calculi? (4)

Answer 13

Obstruction.
Haematuria.
Infection.
Squamous cell metaplasia ± carcinoma.

Question 14

What are the risk factors for renal carcinoma? (6)

Answer 14

Tobacco.
Obesity.
Hypertension.
Oestrogens.
Acquired cystic kidney disease.
Asbestos exposure.

Question 15

What is the most common type of renal cell carcinoma?

Answer 15

Clear cell.

Question 16

What is Von-Hippel-Lindau syndrome?

Tumours? (3)

Answer 16

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.

Question 17

How does renal cell carcinoma present? (4)

Answer 17

Hameaturia, palpable abdominal mass, costovertebral pain.

25% with systemic symptoms/metastasis.

Question 18

What are the paraneoplastic syndromes associated with renal cell carcinoma? (3).

Answer 18

Cushing’s (ACTH).
Hypercalcaemia (Parathyroid hormone related peptide).
Polycythaemia (erythropoietin).

Question 19

Name two rare types of renal cell carcinoma?

Answer 19

Papillary.

Chromophobe.

Question 20

What is the morphology of clear cell renal carcinoma?

Microscopy? (4)

Answer 20

Well defined yellow tumour with haemorrhage areas.

Clear cells, delicate vasculature, small and pale nuclei.

Question 21

What is the morphology of papillary renal carcinoma?

Microscopy? (3)

Answer 21

Cystic and multiple tumours.

Cuboidal, foamy cells with surrounding fibrovascular cores with macrophages.

Question 22

What is urothelial (transitional) cell carcinoma and where may it arise?

Answer 22

Arises from specialised multilayered epithelium.

Most common in bladder, but anywhere from renal pelvis to urethra.

Question 23

What are the risk factors for urothelial (transitional) cell carcinoma? (6)

Answer 23

Age.
M > F.
Carcinogens: smoking, arylamines, cyclophosphamide, radiotherapy.

Question 24

How does urothelial (transitional) cell carcinoma commonly present? (4)

Answer 24

Haematuria - most common.
Urinary frequency.
Pain on urination.
Urinary tract obstruction.

Question 25

What are the four histological patterns seen in urothelial (transitional) cell carcinoma?

Answer 25

Papilloma-papillary (most common).
Invasive papillary.
Flat non-invasive papillary.
Flat invasive.

Question 26

What is the prognosis of urothelial (transitional) cell carcinoma?

Answer 26

Low grade: 98% 5 year survival.

Muscle invasion: 60% 5 year survival.