Primary intestinal lymphoma with paraproteinemia.

Five cases of primary intestinal lymphoma are described. The main clinical features included abdominal pain, diarrhea, and marked weight loss, together with radiologic and some laboratory findings suggestive of malabsorption. Laparatomy perfomed in four cases revealed dilatation of the small intestine, with mesenteric node enlargement. In these four instances there was a definite histologic evidence of malignant lymphoma, either initially or later in the course of the disease. A characteristic feature here was the diffuse infiltration of the intestinal mucosa with plasma cells, which in the deeper layers became progressively atypical and were mixed with histiocytes and giant cells. A similar infiltrate was seen in the mesenteric nodes. Immunoelectrophoresis showed the pattern of IgA heavy chain disease. It is suggested that the latter is a variant of primary intestinal lymphoma and not a separate disease entity.