EXPRESSION OF THE MUCOSAL HOMING RECEPTOR ALPHA-4-BETA-7 IN MALIGNANT LYMPHOMATOUS POLYPOSIS OF THE INTESTINE

Recent studies have identified the integrin alpha 4 beta 7 as a mucosal homing receptor that mediates lymphocyte migration to the intestinal mucosa by binding to MAdCAM-1, which is a vascular recognition molecule (adressin) selectively expressed on mucosal endothelium. The expression of the alpha 4 beta 7 mucosal homing receptor was studied in eight cases of malignant lymphomatous polyposis (MLP). This unusual presentation of non-Hodgkin's lymphoma of mantle cell type is characterized by multifocal lymphomatous involvement of the gastrointestinal tract. Unlike nodal mantle cell lymphomas, cases of MLP showed expression of alpha 4 beta 7, suggesting that this homing receptor plays an important role in determining the characteristic mucosal dissemination pattern of MLP.