Constipated plasma cells associated with monomeric macroglobulinemia

Low molecular weight macroglobulinemia was observed in a patient with chronic pulmonary infection. An enlarged cervical lymph node contained many abnormal plasma cells, which were distended with immunoglobulin; this material appeared to be released into lymph spaces when the cells burst. The macroglobulin production is considered to be a non-neoplastic reactive immune response to the pulmonary infection. It is postulated that the association of constipated plasma cells and 7s-IgM can best be explained as an acquired defect in macroglobulin polymerization.