Gastrointestinal mucosa and primary gastrointestinal lymphoma

The primary gastrointestinal lymphomas in Shiraz, Iran, and Richmond, Virginia, USA were compared. Upper duodenojejunal lymphoma is always associated with atrophy of the surrounding nonlymphomatous mucosa, plasma cell infiltration and formation of lymph follicles. This is frequently linked to repeated gastroenteritis leading to mucosal atrophy, mutation of plasma cell precursors and secretion of alpha-heavy-chain. Gastrointestinal lymphoma in the USA and other industrialized countries is found in the stomach, where it is accompanied by superficial perifoveolar plasma cell gastritis of the surrounding mucosa, or in the performed lymphoid tissue of the ileocolon, surrounded usually by normal mucosa. A hypothesis for the pathogenesis of the different types of primary gastrointestinal lymphoma, considering the geographic distribution, and mucosal and immunologic antecedents, is presented.