# Radiotherapy for Large Mucosa-Associated Lymphoid Tissue Lymphoma of the Rectum: A Case Report

## TL;DR

A rare case of large rectal MALT lymphoma was successfully treated with radiotherapy, showing no recurrence after 29 months.

## Contribution

This case report presents radiotherapy as a potential definitive treatment for large rectal MALT lymphoma.

## Key findings

- Radiotherapy at 39.6 Gy in 22 fractions resulted in complete metabolic response in a patient with large rectal MALT lymphoma.
- The patient remained recurrence-free for 29 months post-treatment with no severe adverse events.
- Radiotherapy is suggested as a viable treatment option for large rectal MALT lymphomas.

## Abstract

Mucosa-associated lymphoid tissue (MALT) lymphomas may arise at various sites, but MALT lymphoma of the rectum is rare. Several treatment options are available for MALT lymphoma of the rectum; however, no standard treatment has been clearly defined. Herein, we report a case of large-sized MALT lymphoma of the rectum that was successfully treated with radiotherapy. The patient presented to the hospital with a complaint of bloody stools and, after a biopsy, was diagnosed with MALT lymphoma of the rectum. Before treatment, the tumor size was 50 × 62 × 70 mm. Radiotherapy was administered at a total dose of 39.6 Gy in 22 fractions, and the patient achieved a complete metabolic response two months after treatment. The patient was followed up for 29 months after radiotherapy, and no recurrence or severe adverse events were observed. This report demonstrates that radiotherapy may be a definitive treatment option for large-sized MALT lymphomas of the rectum.