Crossed fused renal ectopia with metastatic renal cell carcinoma

The patient is an 83-year-old man with a 4-month history of right arm pain. He had no previous history of cancer. Radiographs showed a minimal pathologic fracture of the proximal right humerus with new callus formation at the fracture site. A bone scan was done but did not demonstrate other areas of involvement. However, it was noted that the patient did not appear to have a left kidney, and there were 2 areas of increased uptake in the region of the right kidney. A CT scan of the abdomen and pelvis was done and showed a crossed fused ectopic kidney with a 3 X 4 cm mass on its inferior pole. A biopsy of the right humerus lesion confirmed that it was metastatic renal cell carcinoma, and the patient underwent a nephrectomy of the involved kidney.