A Rare Case of Synchronous Fetal Type Adenocarcinoma and Mucinous Adenocarcinoma of the Lung Evaluated by 18F-FDG PET/CT

A 71-year-old man underwent F-FDG PET/CT for metabolic characterization of pulmonary nodules. F-FDG PET/CT showed increased tracer uptake in a 3.5-cm left upper lobe mass. A second lesion (1.5 cm) characterized by poor F-FDG uptake was described in the same lobe. Based on these findings, the patient underwent upper left lobectomy. Histology demonstrated 2 synchronous tumors. The F-FDG-avid lesion was a rare moderately differentiated fetal type adenocarcinoma, whereas the second lesion with low F-FDG uptake was a moderately differentiated mucinous adenocarcinoma. In our case, F-FDG PET/CT has been useful in metabolic characterization and staging of these synchronous rare pulmonary tumors.