Tumours of the kidney, [s8]rare

In Europe tumours of the kidney are about tenth in order of frequency, the more common varieties being: adenocarcinoma (hypernephroma) (75%), tumours of the renal pelvis (10%), nephroblastoma (Wilm's tumour, 8%), and squamous cell carcinoma 2%. In Africa nephroblastoma is the most common.

Adenocarcinomas present between the ages of 40 and 70, as haematuria (60%), an enlarged kidney (20%), or with symptoms of secondary spread, such as general ill health and bone pain. Otherwise, pain is not a major feature, unless the patient has haematuria and clot colic.

KIDNEY TUMOURS ADENOCARCINOMA SPECIAL TESTS. A good quality intravenous urogram will demonstrate most renal masses. Look for displacement, deformity, and destruction of the calyces of the patient's kidney. The tumour is usually in the upper or lower poles. Ultrasound readily distinguishes solid from cystic lesions, but you are unlikely to have this. If he has haematuria, cystoscope him (23.3). Look for ''cannon ball' secondaries in his lungs.

THE DIFFERENTIAL DIAGNOSIS includes: (1) Renal cysts (the commonest cause of a renal mass) and hydronephrosis. The kidney is palpable but haematuria is unusual. (2) Polycystic kidney (a mass and haematuria). (3) An enlarged spleen. (4) Other tumours of the kidney and large gut. Not all renal cysts and hydronephrotic kidneys are palpable, and the absence of haematuria does not exclude a carcinoma.

THE PROGNOSIS depends on the stage at which the diagnosis is made.

If the tumour has not spread outside the renal capsule (less than 50% of cases, even in Europe), the 5 year survival is 30% and the 10 year survival 7%.

If it has spread outside the renal capsule, there are few 5 year survivors.

MANAGEMENT. If he has no obvious metastases, refer him for nephrectomy. It may reverse some of the systemic effects of the tumour (anaemia, myopathies, etc.), even if he does have metastases.

OTHER RENAL TUMOURS If he has a TRANSITIONAL CELL TUMOUR of his renal pelvis, it is likely to be associated with similar tumours in his bladder. Diagnose it in the same way as an adenocarcinoma. These tumours usually project into the renal pelvis, so that you can see them on a retrograde urogram. Nephrectomy, including removal of the ureter where secondaries may develop, has a better prognosis than with an adenocarcinoma.

If he has a SQUAMOUS CELL CARCINOMA, it is likely to be associated with chronic infection, and a curative nephrectomy is seldom possible.

If you think he might have a NEPHROBLASTOMA, see Section 23.6.