Published online Dec 28, 2014. doi: 10.3748/wjg.v20.i48.18487
Revised: August 18, 2014
Accepted: October 15, 2014
Published online: December 28, 2014
Processing time: 184 Days and 22.7 Hours
Colonic mucosa-associated lymphoid tissue (MALT) lymphomas are a rare occurrence and the definitive treatment has not been established. Solitary or multiple, elevated or polypoid lesions are the usual appearances of MALT lymphoma in the large intestine and sometimes the surface may reveal abnormal vascularity. Herein, we report a case of MALT lymphoma and review the relevant literature. Upon colonoscopy, a suspected pathologic lesion was observed in the proximal transverse colon. The lesion could be distinguished more prominently after using narrow-band imaging mode and indigo carmine-dye spraying chromoendoscopy. Histopathologic examination of this biopsy specimen revealed lymphoepithelial lesions with diffuse proliferation of atypical lymphoid cells effacing the glandular architecture and centrocyte-like cells infiltrating the lamina propria. Immunohistochemical analyses showed that tumor cells were positive for CD20 and Bcl-2e, and negative for CD10, CD23, and Bcl-6. According to Ann-Arbor staging system, the patient had stage IIE. A partial colectomy with dissection of the paracolic lymph nodes was performed. Until now, there is no recurrence of lymphoma at follow-up.
Core tip: Mucosa-associated lymphoid tissue (MALT) lymphoma in the large intestine is a rare disease, but it is a clinically important condition that requires proper evaluation. Most of the colonic MALT lymphomas mainly present as a protruding and/or ulcerative lesion, and rarely present as a flat lesion. It is not easy to detect MALT lymphoma of the flat type and could be misdiagnosed. Thus, greater attention is needed for the detection and differential diagnosis of these lesions. The narrow-band imaging mode plus indigo carmine-dye spraying chromoendoscopy or/and endoscopic biopsy may be helpful for making the diagnosis.