Introduction

Cancer of the kidney represents 3% of adult malignancies. There are about 6500 new cases per year diagnosed in England and Wales, occurring most commonly between the ages of 50 and 70 years. Men are more frequently affected than women. More than 30% of patients present with metastatic disease. The majority of malignant tumours are adenocarcinomas, arising from the proximal renal tubular epithelium. These tumours were previously called hypernephroma because it was believed that they originated from adrenal rests, but they are correctly termed renal cell carcinoma (RCC). Transitional cell carcinoma of the renal pelvis accounts for 5% of all renal malignancies, and is covered separately at the end of the chapter.

Types of kidney tumour

Kidney tumours can be benign, malignant primary or metastatic. Benign tumours include cysts (simple, complex, multiple), inflammatory (infection, infarction), adenoma, and oncocytoma. Malignant primary tumours include RCC, lymphoma, sarcoma and renal pelvis tumours (5% of malignant renal cancers arise from the renal pelvis, and more than 90% of these are transitional cell carcinoma).

Anatomy

The kidneys are retroperitoneal structures that lie between the 11th rib and the transverse process of the 3rd lumbar vertebral body, each approximately 11 cm in length, the right lying slightly lower than the left. Each kidney is surrounded by perinephric fat which in turn is covered by Gerota's fascia. The right kidney abuts the liver and stomach and the left, the spleen, stomach, and pancreas.