Endoscopic removal of primary B‐cell mucosa‐associated lymphoid tissue lymphoma of the cecum

Abstract

A 61‐year‐old woman with a history of positive fecal occult blood test was referred for further evaluation. She was symptom‐free and had no family history of colorectal cancer. Colonoscopy revealed a semipedunculated polyp with a surface of normal appearance. Although a biopsy specimen revealed inflammatory cells including numerous small lymphocytes in the mucosa, a definitive diagnosis was not made. Four weeks later, endoscopic removal using the submucosal injection method was performed for diagnosis as well as treatment. The tumor measured 14 × 13 × 6 mm. The pathological diagnosis was low‐grade B‐cell mucosa‐associated lymphoid tissue (MALT) lymphoma, and the depth of invasion was estimated as the submucosal layer. The case described here suggests that MALT lymphoma should be added to the differential diagnosis of colorectal submucosal tumors, and some cases of them might be resected endoscopically using the submucosal injection method.