Radiotherapeutic Outcomes for Localized Primary Rectal Mucosa-Associated Lymphoid Tissue Lymphoma: A Consecutive Case Series of Three Patients.

Gastrointestinal malignant lymphoma is uncommon and accounts for a small proportion of all gastrointestinal neoplasms. Primary rectal extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALToma) is a rare type of intestinal lymphoma. Here, we report about three patients (two females, one male) with localized rectal MALToma who were treated with external beam radiation therapy (EBRT). The median age of the patients was 59 years (range: 50-67 years). Chemotherapy or eradication therapy was not performed before EBRT. All patients received a radiation dose of 30 Gy in 15 fractions using X-ray photon beams. Pathological examination confirmed complete remission of rectal MALToma after EBRT in all patients. At approximately five years after EBRT, none of the patients showed any evidence of recurrence of rectal MALToma. The use of EBRT resulted in excellent disease control, and no severe radiation-induced toxicity was observed. These results suggest that EBRT is a useful treatment modality for primary rectal MALToma.