A case of small cell carcinoma of the esophagus detected incidentally by FDG-PET.

Small cell carcinoma (SmC) of the esophagus is rare, and is sometimes impossible to detect by macroscopic inspection using an endoscope or histological examination of biopsied specimens. A 73-year-old man received F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) to evaluate the response to radiofrequency thermal ablation therapy for lung cancer. FDG-PET showed abnormal accumulation in the posterior mediastinum. Endoscopy disclosed ulcerous lesions with marginal elevation in the middle segment of the esophagus, but the biopsy specimen taken concurrently was not malignant histologically. FDG-PET, performed two months later, revealed abnormal accumulation in the suspect area, and the extent of accumulation was wider than previously. Histological examination of the specimen biopsied during the endoscopy led to a diagnosis of SmC. FDG-PET thus proved useful in the early detection of SmC.