Renal Cell Carcinoma

Adenocarcinoma of the renal cortex; most common type of kidney tumour

Aetiology

Risk factors

  • Smoking
  • Renal failure and dialysis
  • Obesity
  • Hypertension
  • Low socio-economic status
  • Asbestos, cadmium exposure, phenacetin
  • Genetic
    • VHL accounts for most sporadic renal cancers
    • 50% of cases of VHL syndrome will develop RCC

Pathophysiology

  • Believed to arise from the proximal convoluted tubule
  • 10-25% contains cysts or are predominantly cystic
    • Bosniak score used to predict cancer vs cystic kidney disease

Histological classification

  • Conventional clear cell carcinoma (80%) - loss of VHL
    • Clear cells - cytoplasm rich in lipids and glycogen 3p deletion
  • Papillary (10-15%)
    • Elongated papillae often with foamy cells
  • Chromophone (5%)
    • Large cells with defined cell borders
    • Atypical nuclei resembling raisins - 'raisinoid'
    • Histologically similar to oncocytomas
  • Collecting duct - rare, young patients, poor prognosis
    • Most aggressive cancer
    • High grade carcinoma of mixed cell type
  • Medullary cell - young sickle cell patients, very poor prognosis

Spread

  • RCC has a propensity for renal vein involvement and can even extend into vena cava and grow up towards the heart

Clinical presentation

  • Haematuria, loin pain, mass - all 3 together in less than 10% of cases
  • Pyrexia of unknown origin (8-9%)
  • Varicocoele
  • Paraneoplastic syndrome
    • Polycythemia - renal cell carcinoma may produce excessive erythropoietin (EPO)
    • Hypertension - increased renin production by the tumour
    • Hypercalcaemia - parathyroid hormone-related peptide (PTHrP) produced by the tumour

Investigations

  • USS
  • CT chest abdomen, pelvis for staging
  • FBC
  • Renal and liver function

Management

Small tumours < 3-4 cm

  • Surveillance in elderly unfit patients
  • Ablation techniques in fit, elderly patients and selected younger patients
  • Partial nephrectomy

> 3-4 cm

  • Surveillance, ablative techniques
  • Partial nephrectomy
  • Radical nephrectomy

Large tumours

  • Radical nephrectomy

Follow-up

  • FBC, renal and liver functions
  • Imaging - CT/USS + CXR
  • Duration 5-10 years