[A case of primary sigmoid colon mucosa-associated lymphoid tissue lymphoma].

The gastrointestinal (GI) tract is the most frequently involved site of mucosa-associated lymphoid tissue (MALT) lymphoma. Stomach is the most common site of involvement among the GI tract. However, MALT lymphoma of the large intestine is rare. A diagnosis is established by pathological examination of the surgical or endoscopic specimens. A 72-year-old man with low abdominal pain was diagnosed as a sigmoid MALT lymphoma, which was noted as an obstructing mass in a colonoscopic examination. A left hemicolectomy was performed, and the patient has had no recurrence postoperatively without any chemotherapy.