ACUTE MONOCYTIC LEUKEMIA - A SINGLE INSTITUTION EXPERIENCE

Using strict FAB criteria, 39 cases of monocytic leukemia were identif ied in 463 consecutive cases of AML. Patients had a median age of 49 w ith no sex predominance. Extramedullary disease and hyperleukocytosis were common (54% and 36% of patients respectively). Cytogenetic analys is was successful in 38 of 39 patients; 71% had a cytogenetic abnormal ity and 42% of these involved chromosome 11; 14 of 16 chromosome 11 ab normalities involved the region of 11q23. Non-chromosome 11 abnormalit ies tended to occur in older patients and to be associated with a lowe r platelet count; patients with the translocation 9;11 tended to have a lower white count and a higher incidence of therapy-related leukemia , 35 patients were treated with induction therapy including intensive chemotherapy (n = 33) and allogeneic BMT at presentation (n = 2). Pati ents who entered remission underwent consolidation chemotherapy, autol ogous BMT, or allogeneic BMT depending on policies at the time of diag nosis. Of 6 patients who underwent further intensive chemotherapy ther e is 1 long-term disease-free survivor. 3 of 8 patients undergoing aut ologous BMT and 2 of 3 patients undergoing allogeneic BMT are long-ter m disease-free survivors. We conclude that this specific subtype of AM L, relatively rare when strict criteria are applied, is associated wit h unique biologic and clinical features and that the high relapse rate associated with conventional therapy makes new treatment approaches i nvolving stem cell transplantation or immunomodulation necessary.