Malignant lymphoma of mucosa associated lymphoid tissue: a new etiology of amyloidosis.

Non Hodgkin Malignant lymphomas (NHML) of mucosa associated lymphoid tissue (MALT) are known to have multiple involvement of the digestive tract. We report one case, presenting with an infiltrative process of the jejuno-ileum, associating lymphoplasmacytoid proliferating cells and amyloidosis. The plasmacytoid cells expressed Alpha and scarce Mu heavy chains, and lambda light chain. Lympho-epithelial lesions were more obvious at the second site of involvement, in the gastric mucosa. The amyloid substance was negative with the Amyloid A component antibody and gave a background noise with Alpha, Mu and lambda chains. No similar report of amyloidosis associated with MALT NHML has been found in the literature.