Asymptomatic renal neoplasms in the rectal cancer patient.

Although cancers of the rectum and kidney are common malignancies the incidence of coexistent rectal and renal primary tumors is unclear. Our objective was to determine the true incidence of synchronous neoplasms of the rectum and kidney. The computed tumor registry database at the City of Hope National Medical Center was queried for patients with synchronous rectal cancer and renal neoplasms presenting between August 1990 and August 2000. During the 10-year period there were 182 patients presenting for treatment of rectal carcinoma. Of these seven (3.8%) were found to have an asymptomatic renal neoplasm. Four patients underwent synchronous resection. Three patients underwent staged renal and rectal resections. The pathology of the renal lesions included renal cell carcinoma in six and an oncocytoma in one patient. Rectal lesions were all adenocarcinomas and all were within 10 cm of the dentate line. Three patients required abdominoperineal resections and four were treated with low anterior resections. Two patients presented with hepatic metastasis at the time of diagnosis. Five patients remain free of disease. Two patients died of persistent and recurrent disease 6 months and 40 months after operation. With the exception of one patient who required prolonged intubation because of severe Parkinson's disease there were no major complications after simultaneous resection of both renal and rectal disease. Simultaneous asymptomatic renal neoplasms may be found in up to 3.8 per cent of patients with rectal cancer. Synchronous lesions may be treated simultaneously without significant morbidity.