Primary mucosa-associated lymphoid tissue lymphoma of the esophagus, manifesting as a submucosal tumor.

We report a case of primary mucosa-associated lymphoid tissue (MALT) lymphoma in the esophagus that manifested as a large submucosal tumor (SMT). Primary esophageal lymphoma is very rare, occurring in less than 1% of all patients with gastrointestinal lymphoma. Only a few cases of MALT lymphoma in the esophagus have been reported in the English literature. A 53-year-old man was referred to Dongguk University Ilsan Hospital (Goyang, Korea) in July 2012 for further evaluation and treatment of an esophageal SMT. Endoscopy showed a cylindrically elongated submucosal mass with normal overlying mucosa in the mid esophagus, 25-30 cm from the incisor teeth. He underwent surgery to confirm the diagnosis. Pathologic findings showed diffuse small atypical lymphoid cells which were stained with Bcl-2, CD20, but not with CD3, CD5, CD23, Bcl-6, or cyclin D1. These cells showed a positive monoclonal band for immunoglobulin heavy chain gene rearrangement. Based on the pathological, immunohistochemical, and molecular biological features, the esophageal mass was diagnosed as extranodal marginal zone B-cell lymphoma of the MALT type.