Renal cell carcinoma detected on Tc-99m-labeled red blood cell imaging.

A 61-year-old-man with persistent anemia was referred for a Tc-99m-labeled red blood cell (RBC) scan to detect any source of gastrointestinal bleeding. RBC scintigraphy revealed a hypervascular mass in the left renal fossa with functional loss in that kidney, suggesting the possibility of a renal cell carcinoma (RCC). Computed tomography confirmed this.