Malignant histiocytosis resistant to anthracycline. Response to intensive treatment with etoposide and amsacrine.

A 36-year-old woman, presenting with fever, pancytopenia, hepatosplenomegaly, and striking effacement of the bone marrow by true malignant histiocytes, was found to have no benefit from the systemic administration of cyclophosphamide, vincristine sulfate, doxorubicin, prednisone, and high-dose methotrexate with calcium leucovorin rescue. Striking histologic and clinical improvement was noted after the administration of two cycles of etoposide and amsacrine, each cycle consisting of 100 mg/sq m/day of each agent for five days. We believe that this therapy should be considered for future patients demonstrating aggressive presentations of malignant histiocytosis.