[18F]FDG- PET/CT in Staging and Restaging of Fetal Type Adenocarcinoma of the Lung: A Case Report and a Review of the Literature.

Fetal type adenocarcinoma (FTA) is a rare malignant tumor of the lung that histologically resembles an embryonic lung. Due to its rarity, no studies had investigated the possible role of the 18F-fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG PET/CT) in the initial assessment and/or in the restaging of the disease yet. We present a case of a male patient with tongue carcinoma and incidental findings of well-differentiated FTA at [18F]FDG PET/CT. The patient was treated by specific therapy and also performed a subsequent [18F]FDG PET/CT scan that showed a significant reduction of the uptake on lung lesion. This case highlights the potential role and usefulness of PET imaging for staging and posttherapeutic restaging of well-differentiated FTA. The review of the available literature underlined the rarity of the disease since only seven reports were present. Anyway, a possible role of the [18F]FDG PET/CT in the staging of FTA is conceivable.