PET/CT imaging of burned out testicular seminoma with abdominal metastases

Learning Objectives 1. To present the epidemiology, metastatic pathways, and anatomic and functional imaging features of burned out testicular seminoma, and 2. To emphasize the impact of PET/CT imaging in the detection and management of hypermetabolic metastases from spontaneously regressed testicular germ cell neoplasms.

Burned out testicular seminomas are spontaneously and completely regressed primary germ cell malignancies of testes usually associated with active distant metastases. These secondary lesions are frequently detected incidentally by anatomic and functional imaging without any obvious testicular neoplasm during the evaluation of other unrelated diseases or tumors. The authors present two such cases detected during F-18 FDG PET/CT staging of head and neck cancer, and staging of presumed primary duodenal undifferentiated adenocarcinoma respectively. These two cases illustrate the usual pathway of retroperitoneal nodal metastasis and the uncommon seminomatous dissemination, in less than 5% of all cases, to the duodenum and jejunum.