False-positive finding in FDG-PET in a patient with seminoma and sarcoidosis

Abstract

A 33-year-old white man with testicular cancer (seminoma) stage IIIa showed a response in mediastinal lymph node metastases after chemotherapy. However, the tumor markers increase slightly, and therefore an ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography was performed. Multiple FDG avid lesions were found in lymph node, liver and bone. The standardized uptake value (SUV) was discrete increase with a value of 2·8 to 5·7, which is more typical for inflammatory disease than a malignancy. The histological findings in a mediastinal lymph node reported a sarcoidosis, and therefore all lesions were diagnosed as a sarcoidosis. The one-year follow-up showed no further increase in tumor markers and no evidence for metastases.

Keywords:

• FDG-PET
• Sarcoidosis
• Seminoma
• Bone involvement