Ring-like uptake pattern of a skeletal imaging agent in a huge renal cell carcinoma

A case of huge renal cell carcinoma with localization of a skeletal imaging agent is presented. Two unusual scintigraphic findings of bone agent localization in the tumor were observed: a ring-like configuration, and low-intensity uptake. The large ring-like appearance of the extraosseous radioactivity may reflect a bulky tumor with central necrosis and a less active calcification process.