Diffuse plasma cell infiltration of the small intestine with malabsorption associated to IgA monoclonal gammapathy

A 30-year-old woman had clinical and biochemical malabsorption characteristics; roentgenograms disclosed a diffuse infiltrative process in the small intestine. The electrophoretic proteinogram revealed a homogeneous band in the gamma globulin area, which on immunoelectrophoretic studies corresponded to an IgA-kappa immunoglobulin. Intestinal biopsies showed total atrophy of the villi and a massive mature plasma cell infiltration of the lamina propria and mesenteric lymph nodes. The skeletal roentgenographic survey and bone marrow were normal. This case fits the criteria used to define “diffuse plasma cell infiltration of the small intestine, with malabsorption but without lymphoma,” with an associated IgA-kappa monoclonal gammapathy. At autopsy 8 months later, a multicentric intestinal malignant plasma cell tumor was diagnosed.