Malignant Histiocytosis Results of Combination Vincristine-Prednisone Therapy

Two patients manifested the typical clinical and pathological features of malignant histiocytosis. Objective remissions of 3 months and 2 months, respectively, were induced by combination chemotherapy with vincristine and prednisone. The patients eventually died from complications of this rapidly progressive and uniformly fatal illness without significant prolongation of survival time. Combined chemotherapy may be useful for induction of remission in this disorder, and suitable maintenance programs should be developed. M ALIGNANT histiocytosis is a rapidly progressive and usually fatal disease characterized by an invasive proliferation of morphologically atypical histiocytes in multiple organs (1). The disease was first de-scribed as a separate clinical entity by Scott and Robb-Smith (2) , who labeled it "histiocytic medullary reticulosis. " Its low prevalence has made difficult the study of effectiveness of single drug chemotherapy in a large series of patients. In general, the experience with single drug therapy, except for high-dose pred-nisone therapy in three patients (3-5), has been dis-appointing. Failure to palliate symptoms or prolong survival has been reported with vincristine (6) , pred-nisone (3,7-9) , Cytoxan ® ( 3, 9, 1 0) , nitrogen mustard (11), and antibiotics with or without trans-fusions (12-15). Two cases of malignant histio-cytosis in which temporary but definite remissions were induced with vincristine-prednisone combined therapy are presented