32 - Renal system 2

Question 1

Causes of urinary tract obstruction - pelvis

Answer 1

Calculi
Tumours
Ureteropelvic stricture

Question 2

Causes of urinary tract obstruction - ureter-intrinsic

Answer 2

Calculi
Tumours
Clots
Sloughed papilae 
Inflammation

Question 3

Causes of urinary tract obstruction - ureter-extrinsic

Answer 3

Pregnancy
Tumours
Retroperitoneal fibrosis

Question 4

Causes of urinary tract obstruction - prostate

Answer 4

Hyperplasia
Carcinoma
Prostatitis

Question 5

Functional obstruction of urinary tract

Answer 5

Neurological conditions

Severe reflux

Question 6

Sequelae

Answer 6

Infection - cystitis, ascending pyelonephritis

Stone/calculi formation

Kidney damage - acute or chronic

Question 7

Consequences of urinary tract obstruction dependent on…

Answer 7

Site
Degree of obstruction
Duration

Question 8

Urinary tract obstruction - clinical presentation

Answer 8

Acute bilateral obstruction -> pain, acute renal failure & anuria

Chronic unilateral obstruction -> asymptomatic, but will go to cause corticol atrophy and reduced renal function

Bilateral partial obstruction -> initially polyuric with progressive renal scarring and impairment

Question 9

Renal calculi/urolithiasis- epidemiology

Answer 9

7-10% of population + increasing
Male
Peak onset 20-30

Question 10

Renal calculi/urolithiasis - pathogenesis

Answer 10

Either due to excess of precipitating substances e.g. Ca

Or change in urine constituents (pH)

Poor urine output - supersaturation

Decreased citrate levels

Question 11

Renal calculi/urolithiasis - classification of stones

Answer 11

Calcium (70%) - calcium oxalate
Struvite stones (15%) - magnesium ammonium phosphate
Urate stones (5%) - uric acid
Cystine stones (1%)

Question 12

Calcium stones - cause

Answer 12

Hypercalciuria due to: hypercalcaemia, excessive absorption of intestinal Ca2+, inability to reabsorb tubular Ca2+, idiopathic

Other risk factors = gout, hyperoxaluria

Question 13

Causes of hypercalcaemia

Answer 13

Bone disease
PTH excess
Sarcoidosis

Question 14

Process of struvite stone formation

Answer 14

1. Urease producing bacterial infection
2. Urease converts urea to ammonia
3. Causes a rise in urine pH
4. Precipitation of MgNH4 phosphate salts
5. Large ‘staghorn’ calculi

THERE IS A PICTURE OF A STAG

Question 15

Urate stones

Answer 15

Hyperuricaemia

Gout
Or patients with a high cell turnover e.g. leukaemia

Idiopathic

Question 16

Cystine stones

Answer 16

Rare

Occur in the presence of an inability of kidneys to reabsorb amino acids

Question 17

Renal calculi - investigations

Answer 17

Non-contrast CT scanning (gold standard) 95% sensitive

US in pregnancy or where CT not possible (30-67% sensitive)

IV urography (70% sensitive) for stones

Question 18

Sequelae definition

Answer 18

Secondary condition so caused by another

Question 19

Sequelae for renal

Answer 19

Obstruction
Haematuria
Infection
Squamous metaplasia +/- squamous cell carcinoma

Question 20

Renal cell carcinoma

Answer 20

3% of cancers
Vast majority of renal carcinomas are clear cell
In older people M>F

Question 21

Risk factors for renal disease

Answer 21

Tobacco
Obesity
Hypertension
Oestrogens
Acquired cystic kidney disease
Asbestos exposure

Question 22

Von Hippel-Lindau Syndrome - features

Answer 22

Most common of severe cancer syndromes

VHL gene required for breakdown of hypoxia inducible factor-1 (HIF-1) oncogene

Loss of gene function causes cell growth and increased cell survival

Tumours in kidneys, blood vessels and pancreas

Question 23

Von Hippel-Lindau Syndrome - clinical presentation

Answer 23

Local symptoms - haematuria, palpable abdo mass, costovertebral pain

Incidental
Late presentation: systemic symptoms or mets

Paraneoplastic syndromes

Question 24

Paraneoplastic syndrome - what is it?

Answer 24

Clinical syndrome caused by tumours
Not related to the tissue that the tumours arose from
Not related to invasion by the tumour of itself or mets

Question 25

Paraneoplastic syndromes associated with renal cell carcinoma

Answer 25

Cushing’s (ACTH)
Hypercalcaemia (PTH related peptide)
Polycythaemia (EPO)

Question 26

Renal Cell Carcinoma - morphology

Answer 26

Clear cell: well defined yellow tumours often with haemorrhagic areas. May extend into perinephric fat or into renal vein

Papillary - more cystic more likely to multiple

Question 27

Renal Cell Carcinoma - microscopy of clear cell

Answer 27

Clear cell has clear cells - duh.
Delicate vasculature
Small bland nuclei

Question 28

Renal Cell Carcinoma - microscopy of non-clear cell

Answer 28

Papilarry tumours
Cuboidal, foamy cells
Surrounding fibrovascular cores often containing foamy macrophages or calcium

Question 29

Urothelial cell carcinoma - features

Answer 29

95% of bladder tumours
Arising from specialised multilayers epithelium
Most common in bladder but may rise from renal pelvis to urethra

Question 30

Urothelial cell carcinoma - risk factors

Answer 30

Age
Gender (M>F)

Carcinogens - smoking, arylamines, cyclophosphamide, radiotherapy

Question 31

Urothelial cell carcinoma - presentation

Answer 31

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