Renal metastasis from primary colon cancer on FDG PET-CT.

We report the PET-CT appearance of a metastasis from a primary colon cancer to the right kidney in an 84-year-old woman with a history of moderately differentiated adenocarcinoma of the cecum. The patient underwent right hemicolectomy and chemotherapy. Restaging PET-CT study, 4 months after her last chemotherapy, demonstrates a hypermetabolic soft-tissue mass in the inferior pole of the right kidney. The patient subsequently had a right partial nephrectomy. The pathology was consistent with metastatic colonic adenocarcinoma. Renal metastasis from primary colon cancer is very rare.