Renal enlargement

Question 1

Renal Enlargement

Answer 1

This woman has been referred by her GP for investigation of hypertension. Please examine her abdomen.

Question 2

Clinical signs

Peripheral

Answer 2

• Blood pressure: hypertension
• Arteriovenous fistulae (thrill and bruit), tunnelled dialysis line
• Immunosuppressant ‘stigmata’, e.g. Cushingoid habitus due to steroids, gum hypertrophy with ciclosporin

Question 3

Clinical signs

Abdomen

Answer 3

• Palpable kidney: ballotable, can get above it and moves with respiration
• Polycystic kidneys: both may/should be palpable, and can be grossly enlarged (will feel ‘cystic’, or nodular)
• Iliac fossae: scar with (or without!) transplanted kidney
• Ask to dip the urine: proteinuria and haematuria
• Ask to examine the external genitalia (varicocele in males)

Question 4

Associated conditions

Answer 4

• Hepatomegaly: polycystic kidney disease
• Indwelling catheter: obstructive nephropathy with hydronephrosis
• Peritoneal dialysis catheter/scars

Question 5

Causes of unilateral renal enlargement

Answer 5

• Polycystic kidney disease (other kidney not palpable or contralateral nephrectomy –flank scar)
• Renal cell carcinoma
• Simple cysts
• Hydronephrosis (due to ureteric obstruction)

Question 6

Causes of bilateral enlargement

Answer 6

• Polycystic kidney disease
• Bilateral renal cell carcinoma (5%)
• Bilateral hydronephrosis
• Tuberous sclerosis (renal angiomyolipomata and cysts)
• Amyloidosis

Question 7

Investigations

Answer 7

• U&E
• Urine cytology
• Ultrasound abdomen ± biopsy
• IVU
• CT if carcinoma is suspected
• Genetic studies (ADPKD)

Question 8

Autosomal dominant polycystic kidney disease:

Answer 8

• Progressive replacement of normal kidney tissue by cysts leading to renal enlargement and renal failure (5% of end‐stage renal failure in UK)
• Prevalence 1:1000
• Genetics: 85% ADPKD1 chromosome 16; 15% ADPKD2 chromosome 4

Question 9

ADPKD Present with

Answer 9

⚬⚬ Hypertension
⚬⚬ Recurrent UTIs
⚬⚬ Abdominal pain (bleeding into cyst and cyst infection)
⚬⚬ Haematuria
* End‐stage renal failure by age 40–60 years (earlier in ADPKD1 than 2)

Question 10

Other organ involvement in ADPKD

Answer 10

⚬⚬ Hepatic cysts and hepatomegaly (rarely liver failure)
⚬⚬ Intracranial Berry aneurysms (neurological sequelae /craniotomy scar?)
⚬⚬ Mitral valve prolapse

Question 11

Genetic counselling of family and family screening in ADPKD;

Answer 11

10% represent new mutations

Question 12

Treatment of ADPKD

Answer 12

• Nephrectomy for recurrent bleeds/infection/size,
• Dialysis and
• Renal transplantation

Question 13

US diagnostic criteria for ADPKD

Answer 13

• At least 2 cysts in 1 kidney or 1 cyst in each kidney in at risk Pt aged < 30 years
• At least 2 cysts in each kidney in at risk Pt aged 30-59 years
• At least 4 cysts in each kidney in at risk Pt aged > 60 years

Question 14

US diagnostic criteria for ADPKD in Pt with family hx but unknown genotype

Answer 14

• 3 or more unilateral or bilateral renal cysts in pt aged 15-39 years
• 2 or more cysts in each kidney in pt aged 30-59 yeas