BONE-MARROW FINDINGS IN MALIGNANT HISTIOCYTOSIS AND OR MALIGNANT-LYMPHOMA WITH CONCURRENT HEMOPHAGOCYTIC SYNDROME

We examined bone marrow specimens from 19 patients with malignant hist iocytosis (MH) and/or malignant lymphoma (ML) with concurrent hemophag ocytic syndrome (HS) who suffered from high fever, hepatosplenomegaly, liver dysfunction, profound cytopenia, and erythrophagocytosis. There was little lymph-node enlargement or no tumor formation. The neoplast ic cells in 3 patients exhibited histiocytes/macrophages phenotype wit h positive reactions for fluoride-sensitive nonspecific esterase, lyso zyme and CD68 (KP1). Twelve other patients showed a T-cell (CD3) pheno type, in which 5 patients expressed CD30 (BerH2) as well. B-cell chara cteristics with CD20 (L26), CIg. Upsilonlambda and gammakappa were man ifest in 2 patients, but indeterminate markers were found in the 2 rem aining patients. Eighteen patients showed an infiltration of large neo plastic cells mainly with noncohesive interstitial growth pattern, ran ging from 1.7% to 74.2% of the nucleated cells in the bone marrow. A l arge number of histiocytes/macrophages and dendritic cells was diffuse ly observed in 15 patients. Severely decreased hematopoiesis in all th ree series of hematopoietic cells was found in 16 patients. Bone marro w infiltration by the neoplastic cells and numerous reactive cells wit h erythrophagocytosis appears be an important factor of profound cytop enia in patients of MH and/or ML with HS. The infiltrating pattern of the neoplastic and reactive cells in the bone marrow of MH and/or ML w ith HS was different from that of other types of peripheral T-cell ML, B-cell ML in high grade malignancy, and Hodgkin's disease. Cell chara cteristics and lineage of the neoplastic cells in MH and/or ML with HS are also discussed in this study.