Phagocytic myeloma cells in asymptomatic multiple myeloma.

A newly observed case of asymptomatic multiple myeloma in which phagocytic myeloma cells were observed is described. Bone marrow aspirates contained 16% myeloma cells, 2% of which engulfed red blood cells, lymphocytes, and platelets. The possibility is discussed that phagocytizing ability may be one of the markers for malignant plasma cells. Nothing is so far known of the phagocytosis by plasma cells in benign monoclonal gammopathy which is strictly defined.