Cystic disease and tumours Flashcards
Define autosomal dominant polycystic kidney disease. (2)
Autosomal dominant inherited disorder characterised by the development of multiple renal cysts that gradually expands and replace normal kidney substance.
It is variably associated with extra renal (liver and CV) abnormalities.
What gene is affected in autosomal dominant polycystic kidney disease? (2)
85% are mutations in PKD1 (polycystin-1) on chromosome 16.
15% are mutations in PKD 2 (polycystin-2) on chromosome 4
Describe the pathological process in autosomal dominant polycystic kidney disease. (3)
Proliferative/hyperplasia of the tubular epithelium.
Early on, cysts are connected to tubules from which they arise and fluid content is glomerular filtrate.
Later (cyst diameter >2mm), most detach from patent tubule and fluid is formed from epithelial lining.
Enlargement of cysts causes progressive damage to adjacent functioning nephrons.
What are the clinical features of ADPKD? (3)
Presents after 2nd decade
- Acute loin pain due to cyst haemorrhage or infection or stone formation (uric acid stones more common)
- Haematuria
- Abdominal discomfort caused by renal enlargement
- Hypertension
- Progressive renal impairment. ESRF develops in 50% by 50yrs old.
- Liver cysts (clinically insignificant), rarely cysts in pancreas, spleen, ovary and other organs.
- Subarachnoid haemorrhage (intracranial ‘berry’ aneurysms more common)
- Mitral valve prolapse in 20%
How is ADPKD diagnosed? (2)
Examination: abdominal distention and large kidneys, possible hepatomegaly.
USS (or CT): bilateral enlarged kidneys with;
- at least 2 renal cysts if <30 years old
- at least 2 cysts in each kidney between 30-59 years
- at least 4 cysts in each kidney over 60 years.
What is the management of ADPKD? (3)
BP: slows rate of decline in renal function and minimise risk of sub-arachnoid haemorrhage.
Infections: Prompt treatment with antibiotics
Disease progression: by serum creatinine levels
ESRF: renal replacement therapy.
Siblings/children: offered screening by USS in their 3rd decade.
What is medullary sponge kidney? (1)
Uncommon condition characterised by dilatation of the collecting ducts in the papillae, sometimes with cystic change.
Renal function is usually well preserved.
What is the most common renal tumour in adults? (1)
What cell does this arise from? (1)
Renal cell carcinoma
Proximal tubular epithelium
What is medullary sponge kidney? (2)
Uncommon condition characterised by dilatation of the collecting ducts in the papillae, sometimes with cystic change.
Renal function is usually well preserved.
What is the most common renal tumour in adults? (1)
What cell does this tumour arise from? (1)
Renal cell carcinoma (adenocarcinoma) aka clear cell carcinoma)
Proximal tubular epithelium
Name 3 clinical features of a renal tumour. (3)
Loin pain Haematuria Mass in flank Weight loss Malaise Fever Varicocoele (Left) Polycythaemia (rare presentation caused by excess EPO production) Hypercalcaemia (rare presentation caused by secretion of PTH-like substance)
Why can a renal tumour cause a varicocoele? (1)
Which side will the varicocoele affect? (1)
The left gonadal vein drains directly into the renal vein, if a renal tumour obstructs this then a varicocoele will occur.
As the right gonadal vein drains directly into the IVC then a renal tumour will not cause a varicocoele.
Where does renal carcinoma metastasise to? (3)
Bone, liver, brain and lung.
Tumour invades renal vein and IVC causing haematogenous spread
What imaging techniques can be used in diagnosis of renal tumour? (2)
USS: differentiate benign cyst from complex cysts or solid mass
CT: more sensitive then USS for detection and can show involvement of renal vein or IVC
MRI: best for tumour staging.
What is the treatment for a localised renal tumour? (1)
Radical nephrectomy is preferred.
However, partial nephrectomy may be required when there is bilateral involvement, or when contralateral kidney has poor function.
Name 2 choices for locally advanced or metastatic renal carcinoma. (2)
Interleukin-2 or interferon produce remission in 20% of cases.
What epithelium lines that calyces, renal pelvis, ureters, bladder and urethra? (1)
Transitional epithelium
What is the most common location of transitional cell malignancy? (1)
Bladder cancer
Name 3 predisposing factors for development of bladder cancer. (3)
Cigarette smoking
Exposure to industrial chemicals eg aromatic amines or aniline dyes
Exposure to drugs: eg cyclophosphamide
Chronic inflammation eg schistosomiasis (SCC)
How does bladder cancer usually present? (2)
Painless haematuria
Symptoms of UTI but without bacteriuria.
Pain is due to locally advanced disease or metastatic disease.
Dave is a 42 year old man presenting with painless haematuria.
What is the main diagnosis to rule out? (1)
If over 40 and with haematuria, presume urothelial tumour until proven otherwise.
What is the management of a ureteric or renal pelvic tumour? (1)
Nephroureterectomy