Abstract
A case of multiple myeloma whose plasma cells showed hemophagocytosis is reported. A 70-year-old man was diagnosed having multiple myeloma with circulating plasma cells (15%). The plasma cells assumed the morphology of plasmacytoid lymphocytes and 22% of them showed phagocytosis of erythrocytes, platelets, or erythroblasts. Clinically, no osteolytic lesion was found. Immunological marker study revealed 34% of the plasma cells had receptors for C3.
The clinical features of patients with phagocytic plasma cell myeloma in the previous reports were compared with those of common myeloma patients. It is proposed that phagocytic plasma cells tend to migrate to peripheral blood from the bone marrow and have a decreased tendency to form tumor masses.
