REACTIVE PLASMACYTOSIS AND LYMPHOCYTOSIS IN ACUTE MYELOID-LEUKEMIA

The association of plasmacytosis and lymphocytosis with acute myeloid leukemia (AML) has been documented in isolated case reports. We examin ed 149 cases (134 adults, 15 children) of newly diagnosed AML and foun d 9 adults (6%) with greater than or equal to 5% plasma cells and 1 ch ild and 1 adult with greater than or equal to 20% lymphocytes. Lymphoc ytes constituted 25% and 42% of marrow cellularity in the adult and ch ild respectively and persisted throughout remission in the child's mar row. The percentage of morphologically normal plasma cells ranged from 5% to 13% (mean 7%). Monoclonal immunoglobulins were not detected wit h immunostaining or flow cytometry. Hypergammaglobulinemia was present in 3 cases, and a monoclonal increase in IgG-kappa in 1. Plasmacytosi s was not seen in remission marrows from these patients (n=4). Lymphoc ytosis or plasmacytosis occurs in approximately 7% of patients with AM L, appears reactive in nature, and may represent an immunological resp onse to tumor. Monoclonal paraproteins may occur without other evidenc e of B-cell neoplasia.