A case of primary rectal mucosa-associated lymphoid tissue lymphoma treated by endoscopic mucosal resection

A 53-year-old man underwent surveillance colonoscopy that revealed a submucosal tumor-like polypoid lesion on the Rb area of the rectum. Histological examination of biopsy specimens showed chronic inflammation. Endoscopic mucosal resection was performed after obtained informed consent for the purpose of obtaining accurate diagnosis and for curative treatment. Pathological findings of the resected specimen showed low-grade B-cell lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma). Gallium-scintigraphy, abdominal CT, small bowel series and endoscopic examination of the upper gastrointestinal tract revealed no abnormalities. Based on the findings, a diagnosis of stage IE lymphoma was made. However it was suspected that the vertical cut-end of the resected specimen had residue of lymphoma cells. Additional transanal resection of the rectum was therefore performed, but no lymphoma cells were found in the specimen. Eradication of Helicobacter pylori was also performed. Although a standard therapeutic strategy for colonic MALT lymphoma has not been established, endoscopic mucosal resection might be a good therapeutic choice.