[Gamma-heavy chain disease associated with MALT lymphoma of the duodenum].

We report a case of a 63-year-old woman with gamma heavy chain disease (HCD) associated with mucosa-associated lymphoid tissue (MALT) lymphoma of the duodenum. She was suffering from drug-resistant tonsillitis with high fever. Examination on admission showed leukocytopenia and thrombocytopenia. Bone marrow aspirate revealed granulocytosis and a hypocellular marrow with no increase in plasma cells or atypical lymphocytes. Serum electrophoresis disclosed, in addition to hypogamma-globulinemia, an abnormal band due to the presence of gamma HCD protein. This abnormal protein was a molecular weight of approximately 40 kd as determined by Western blots technique, and belonged to the IgG1 subclass as determined by ELISA with monoclonal antibodies against IgG. An endoscopic examination of the patient's duodenum found a small tumorous lesion, which was confirmed pathologically to be MALT lymphoma. HCD is known to be associated with lymphoproliferative diseases. In this case, gamma HCD had developed as a secondary complication of MALT lymphoma. gamma HCD associated with MALT lymphoma of the duodenum is rare in the literature.