Bone-marrow mast cells in lymphoproliferative disorders.

Increased bone-marrow mast-cell content and lymphoproliferative disorders have been previously linked. Using a semiquantitative method we examined bone-marrow mast-cell content in 120 marrow specimens from patients with multiple myeloma, chronic lymphocytic leukemia, non-Hodgkin's lymphoma, and reactive lymphocytosis. Results indicated a statistically significant increase of marrow mast-cell content in patients with chronic lymphocytic leukemia, non-Hodgkin's lymphoma, and reactive lymphocytosis when compared with iron-deficient control subjects (p less than or equal to 0.0005). Patients with multiple myeloma had decreased marrow mast-cell content, clearly separating them from patients with lymphoproliferative disorders and reactive lymphocytosis. Linear regression plot of marrow mast-cell content against percentage of marrow lymphocytes showed a direct relation, indicating that marrow mast-cell density may be related more to the degree of lymphoid proliferation than to the specific lymphoproliferative process. Marrow mast-cell content may therefore be reproducibly determined and used to support the morphologic diagnosis of lymphoproliferative disorders and differentiate them from atypical myelomas.