Monocytic leukemia in infancy. A review of eight children.

The clinical and pathologic features of eight infants with monocytic leukemia are reviewed. The children were all aged 12 months or less at diagnosis and had a high incidence of extramedullary features, skin infiltration being particularly common. The diagnosis was established by conventional morphologic and cytochemical techniques. Using the French-American-British (FAB) classification, five infants had FAB 5a disease, and three had FAB 5b. The difficulties in making the diagnosis from extramedullary sites and the overlap that exists at this age between monocytic leukemia, true histiocytic lymphoma, and malignant histiocytosis are discussed. The treatments given to the group and their response are reviewed. Five of the patients received VP-16-213 and cyclophosphamide as primary induction chemotherapy, a combination that merits further evaluation in leukemia with monocytic features.