Polymastia and renal adenocarcinoma.

After two patients with renal adenocarcinoma were found to have polymastia, we did a survey in which six of 32 patients with renal cancer had this anomaly. This finding is substantially higher than the expected frequency of 0.3 based on surveys of the general population, and accessory nipples were not found in a comparison group of 32 patients with head and neck cancer. An excess of renal anomalies was found among the patients with renal cancer, including duplicate arteries among those with accessory nipples. Family members also seemed prone to renal anomalies and certain neoplasms, notably of the kidney and brain.