Investigation

Investigation of primary renal adenocarcinoma involves:

• microscopy or dipstix testing of urine - positive for blood in two-thirds of cases
• plain abdominal film - may show an abnormal renal outline or occasional calcification
• intravenous urography - previously the screening investigation of choice; typically shows a space-occupying lesion within the kidney distorting the renal outline or calyces
• renal ultrasound - determines whether renal mass is cystic or solid; solid suggests tumour; may reveal invasion of renal vein and inferior vena cava
• abdominal CT – provides information on:
  • function and morphology of contralateral kidney
  • primary tumour extension
  • venous involvement
  • enlargement of locoregional lymphnodes
  • condition of adrenal gland and other solid organs
  • cannot distinguish between hamartomas and adenocarcinoma unless fat is present
• MRI - indicated in patients who are allergic to intravenous CT contrast medium and in pregnancy without renal failure
• arteriography - largely been replaced by CT. It outlines the tumour circulation and may still be used when the patient has only one kidney, or when bilateral renal tumours are suspected, and some renal function may need to be conserved

Detection of metastases:

• chest x-ray - "cannon ball" pulmonary metastases, i.e. a small number of large, well circumscribed, metastatic deposits. Characteristic but not pathognomonic; an identical picture may be noted with testicular tumours.
• liver function tests
• bone scan
• CT (or MRI) of the brain

Other investigations:

• FBC - anaemia is common
• renal function tests
• liver function tests
• tests to determine whether the patient is fit for surgery

Reference:

• (1) Ljungberg B et al. EAU guidelines on renal cell carcinoma: 2014 update. Eur Urol. 2015;67(5):913-24.