LOCALIZED AMYLOIDOSIS AND GASTROINTESTINAL LYMPHOMA - A RARE ASSOCIATION

Aims: Five cases of primary gastrointestinal (GI) lymphoma (three in t he stomach, one in the ileum (IPSID) and one in the colon) associated with localized AL amyloidosis were studied to identify morphological o r immunohistochemical features which could explain the amyloid deposit ion. Methods and results: All the cases were low-grade marginal zone B -cell lymphomas; one case of gastric lymphoma and the IPSID also had a high-grade component. The lymphomas had a monoclonal plasma cell popu lation, with different light and heavy-chain type expression in the fi ve cases, Plasma cell differentiation was closely associated with the amyloid deposits. The latter were an incidental microscopic finding in one case, but produced tumoral masses in the others.Conclusions: The presence of amyloid in primary GI lymphoma is rare, but can have diagn ostic value. In the present study, neither particular features of the lymphomatous proliferation nor specific agents are identified. Therefo re, the factors predisposing to amyloid deposition require elucidation .