Enhanced MRI and 18F-FDG PET/CT Findings of Preoperative Primary Renal Collecting Duct Carcinoma.

Primary renal collecting duct carcinoma is an extremely rare neoplasm. We present a case of preoperative collecting duct carcinoma with enhanced MRI and F-FDG PET/CT findings. The MRI and PET imaging showed a round mass in the left kidney, as well as multiple retroperitoneal lesions with slight enhancement and intense FDG uptake, respectively. A left radical nephrectomy was performed. Primary renal collecting duct carcinoma and retroperitoneal lymph node metastases were confirmed histopathologically.