Radiotherapy for mucosa-associated lymphoid tissue (MALT) lymphoma of the esophagus: a case report with a diagnostic and therapeutic discussion.

Mucosa-associated lymphoid tissue (MALT) lymphoma is increasing common in various sites; however, MALT lymphoma in the esophagus is still rare, so its diagnostic features have not yet been well recognized and optimal treatment has not been properly discussed. Though radiotherapy is widely preferred for gastric and orbital MALT lymphoma, surgery has been the most frequently reported treatment for esophageal MALT lymphoma. This raises the question: why not radiotherapy for esophageal MALT lymphoma instead of surgery? The only reported case of definitive radiotherapy for esophageal MALT lymphoma lacks follow-up data. Three years ago (2007), we treated a 59-year-old male patient with a large esophageal submucosal tumor, diagnosed as MALT lymphoma, with 36 Gy of solo external beam radiotherapy. The tumor was 15 cm in craniocaudal length, homogeneously weakly contrast-enhanced on X-ray computed tomography (CT), homogeneously hypoechoic and clearly demarcated from the surrounding adventitia, and had a concave pattern between the folds. During and after radiotherapy, no treatment-related complications occurred except for transient Grade 2 leukocytopenia. The tumor showed remarkable reduction and histological negativity in the next month. Over the follow-up period, no recurrence was observed in semiannual PET/CT/MRI studies. Taking the current observation with the well known effectiveness of radiotherapy for MALT lymphoma in various other sites, we recommend considering radiotherapy as a reasonable less-invasive treatment for this rare entity.