Radiotherapy for mucosa-associated lymphoid tissue (MALT) lymphoma of the rectum: a case report.

Extra-nodal mucosa-associated lymphoid tissue (MALT) lymphoma is frequently involved with the upper gastrointestinal tract, but rarely involved with the rectum. We report a case of rectal MALT lymphoma treated by radiotherapy (RT) alone. A 74-year-old woman with lower abdominal pain was diagnosed with MALT lymphoma by endoscopic mucosal resection (EMR). She was diagnosed as stage IE (Ann Arbor) MALT lymphoma by diagnostic work-up and review of EMR specimens. Definitive RT was performed with curative intent, totaling 30 Gy in 15 fractions. Complete response was confirmed by colonoscopy after RT with no progression observed at 5 years. Definitive RT is effective for rectal MALT lymphoma.