Two cases of benign esophageal schwannoma with positive FDG-PET findings

Abstract

We report two cases of rare benign esophageal schwannoma showing high uptake of radiotracer on [ 18 F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). Case 1 was a 78-year-old woman with a tumor (50 9 30 9 30 mm) located on the right side of the upper thoracic esophagus. Case 2 was a 70-year-old woman with a tumor (40 9 35 9 27 mm) located in the left anterior wall of the thoracic-to-cervical esophagus. Both tumors were enucleated and histologically diagnosed as benign esophageal schwannoma with nuclear palisading and lymphoid cuffing (Antoni A type). Immunohistochemical staining showed positivity for S-100 protein.There have been five reported cases of esophageal schwannoma with FDG-PET findings, including the present two cases. All five tumors were FDG-PET positive and presented histologically as benign esophageal schwannoma. There was no association between histological malignancy and FDG uptake. We therefore propose that the malignant potential of esophageal schwannomas cannot be evaluated using FDG-PET.