Primary low-grade, B-cell, mucosa-associated lymphoid tissue lymphoma of the colorectum: clinical and colonoscopic features in six cases.

BACKGROUND

Unlike gastric lymphoma, the endoscopic features of low-grade, mucosa-associated lymphoid tissue (MALT) lymphoma of the colorectum have not been defined.

METHODS

We analyzed colonoscopy, endoscopic ultrasonography, and histologic findings in six patients with MALT lymphoma restricted to the colorectum. Histologic confirmation of the proliferation of centrocyte-like cells with lymphoepithelial lesions formed the criteria for the selection of patients.

RESULTS

Based on endoscopic findings, the patients were divided into cases of solitary (4 patients) or multifocal (2 patients) involvement. Endoscopic findings in cases of solitary involvement were uniform in that the lesions were either smooth or nodular protrusions, demonstrated by a hypoechoic mass under endoscopic ultrasonography. Multifocal involvement was endoscopically recognized as protrusions, dilated vasculature, or small ulcers.

CONCLUSIONS

Protruding lesions are the main pattern of involvement in MALT lymphoma of the colorectum, although variable and multifocal involvement is also possible in this type of lymphoma.