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

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