Renal cell carcinoma metastases to the skin: a not so rare case?

To describe the clinical, histological, immunohistochemical and behavioural patterns of the metastases of renal cell carcinoma to the skin.

In a retrospective review of 132 cases of renal cell carcinoma submitted for examination to the Anticancer Institute 'St Savas' nine patients with metastatic disease to the skin were discovered. Clinical data and follow-up information were collected and correlated to tumour behaviour and patient survival. Immunohistochemical studies with epithelial membrane antigen (EMA), vimentin, keratin and carcino-embryonic antigen (CEA) were performed.

In six of the nine patients the skin metastasis was the first evidence of a tumour. Histology of the skin nodule led to identification of the primary site. Histological proof of the renal origin of the tumour was obtained using the above immunohistochemical studies. All patients died from their disease within 3 years of presenting with the skin metastases.

Metastases to the skin from a renal cell carcinoma as first evidence of the disease may not be as rare as the literature describes. Definite proof of the origin of the tumour requires specialized immunohistochemical techniques.