Mucosa-associated lymphoid tissue lymphoma of the esophagus: case report and review of the literature.

We report the histomorphologic and immunohistochemical features of another case of mucosa-associated lymphoid tissue (MALT) lymphoma arising from the esophagus and discuss the problems of differential diagnosis. The patient was a 49-year-old man, who had no gastrointestinal symptoms. On endoscopy, a smooth-surfaced, semibulbous lesion was found 36 cm from the incisors. We performed radical resection of this submucosal tumor with video-assisted thoracoscopic surgery for the purpose of diagnosis and treatment. The immunophenotype of the centrocyte-like-cells was CD20+, BCL2+, CD5-, CD10-, CD23- CD45RO- and cyclin D1-. Diffuse immunostaining of bcl-2 was detected in the nuclei of the tumor cells without lymph follicles. Southern blotting analyses of the IgH gene detected a single dominant band indicative of a clonal IgH rearrangement. From the pathological, immunohistochemical, and molecular biological features we concluded that the tumor was a MALT lymphoma. Only three cases of primary esophageal MALT lymphoma have been reported to date. On the basis of the present case and the three previously reported cases, we suggest that MALT lymphoma of the esophagus is usually an elevated type. The spectrum of sites in which gastrointestinal MALT lymphoma occurs should be expanded to include the esophagus.