FDG PET/CT in Staging and Response Evaluation of Primary Urothelial Carcinoma of the Urethra.

Primary urethral urothelial carcinoma is a rare aggressive tumor with a high propensity for local invasion and regional and distal metastases. We describe the usefulness of FDG PET/CT in management of a patient with primary urethral urothelial carcinoma. FDG PET/CT at initial staging showed FDG-avid primary tumor and lymph node metastasis of the left groin, and mild or no activity of the lung metastases due to small size. FDG PET/CT after 4 cycles of chemotherapy showed progression of the primary tumor and lung metastases, partial response of the left inguinal lymphadenopathy, and multiple new sites of FDG-avid metastases.