Renal Cell Carcinoma - Malignant renal tumours

Renal cell carcinomas (previously called hypernephromas or Grawitz tumours) arise from proximal tubular epithelium. They are the most common renal tumour in adults. They rarely present before the age of 40 years, the average age of presentation being 55 years.

In von Hippel-Lindau disease, an autosomal dominant disorder, bilateral renal cell carcinomas are common and haemangioblastomas, phaeochromocytomas and renal cysts are also found.

Polymorphic probes from chromosome 3p, the region implicated in renal cell carcinoma, have demonstrated genetic linkage between them and von Hippel-Lindau disease. It seems likely, therefore, that mutation of the same tumour suppressor gene may be responsible for both renal cell carcinoma and von Hippel-Lindau disease. Deletion of the short arm of chromosome 3 is the most consistent cytogenetic finding in sporadic tumours.

Diagnosis of Renal Cell Carcinoma

Excretion urography will reveal a space-occupying lesion in the kidney; 10% of these show calcification.

Ultrasonography is used to demonstrate the solid lesion and to examine the patency of the renal vein and inferior vena cava. A renal cell carcinoma too small to cause displacement of the collecting system may be missed on excretion urography.

Ultrasonography and excretion urography are required in the investigation of haematuria (whether microscopic or macroscopic) if one or other investigation carried out initially appears normal. Urography allows diagnosis of calculi and calyceal and other abnormalities which may be missed by ultrasound examination. CT scanning can also be used to identify the renal lesion and involvement of the renal vein or inferior vena cava.

MRI is better than CT for tumour staging. Renal arteriography will reveal the tumour's circulation but is now seldom employed. Urine cytology for malignant cells is of no value. The ESR is usually raised. Liver biochemistry may be abnormal, returning to normal after surgery.

Treatment of Renal Cell Carcinoma

Treatment is by nephrectomy unless bilateral tumours are present or the contralateral kidney functions poorly, in which case conservative surgery such as partial nephrectomy may be indicated.

If metastases are present, nephrectomy may still be warranted since regression of metastases has been reported after removal of the main tumour mass. Severe flank pain may also demand nephrectomy despite the presence of metastases. Radiotherapy has no proven value.

Medroxyprogesterone acetate is of some value in controlling metastatic disease. Treatment with interleukin-2 and α-interferon produces a remission in about 20% of cases. Recently, striking regression of metastases has been reported after non-myeloablative chemotherapy followed by allogeneic (sibling) peripheral blood stem-cell transplantation.

Prognosis of Renal Cell Carcinoma

The prognosis depends upon the degree of differentiation of the tumour and whether or not metastases are present. The 5-year survival rate is 60-70% with tumours confined to the renal parenchyma, 15-35%, with lymph node involvement, and only approximately 5% in those who have distant metastases.