Occasional diagnosis of synchronous renal cell carcinoma during staging of other primary tumors.

Synchronous renal cell cancer (RCC) associated with primary neoplasms of other organs or tissues represents a rare diagnostic report during life. Recently, the widespread use of new diagnostic techniques (echography, computed tomography and magnetic resonance imaging) has permitted diagnosis of clinically silent RCC. We report 6 RCC cases occasionally diagnosed during initial staging of a primary cancer of other organs: 1 rhinopharyngeal carcinoma, 1 gastric cancer, 1 Waldenström's disease, 1 non-Hodgkin's lymphoma, 2 breast cancer, RCC was clinically silent in all patients. The diagnostic problems related to a report of a renal mass in patients with neoplastic disease at other sites and the consequent therapeutic implications are discussed.