Kidney tumours - Genitourinary oncology

Genitourinary oncology

Kidney tumours

Benign tumours are commonly found incidentally at post-mortems or on imaging.

Renal adenomas are derived from renal tubular epithelium. Tumours less than 3 cm in diameter are arbitrarily termed benign adenomas, but histologically they are similar to renal cell carcinomas and have the potential to metastasise.

Oncocytomas are uncommon. Microscopically they contain only large well-differentiated cells with eosinophilic cytoplasm filled with mitochondria.

Angiomyolipomas are associated with tuberose sclerosis, and are hamartomas: tumours composed of smooth muscle, fat and large blood vessels.

Renal fibromas are derived from spindle cells, usually less than 1 cm in diameter and in the medulla.

A rare tumour of the juxta-glomerular cells may present as hypertension in young patients.

Malignant tumours

The most common is renal cell carcinoma (85–90% in adults).

Transitional cell carcinomas of the renal pelvis account for only 5–10%. These share the same pathology as in bladder cancer.

Wilm’s tumour is the most common renal tumour in children.