HYPOCELLULAR ACUTE MYELOID-LEUKEMIA - THE ROCHESTER (NEW-YORK) EXPERIENCE

Fourteen patients with hypocellular acute leukemia (HAL) were reviewed . The median age was 72 years, with an equal male-to-female ratio. Sev ere granulocytopenia with marrow hypocellularity and increased marrow blasts and absence of physical findings were common features. The medi an peripheral blood blast count was 2%. All except 3 cases of erythrol eukemia had marrow blast count that exceeded 30% of all nucleated marr ow cells. All cases were classifiable with the FAB criteria. FAB class ification revealed a preponderance of the M1 category followed by M2 a nd M6 types. The majority of blasts were type 1 and the median myelope roxidase positivity was 14%. Immunophenotyping of bone marrow cells by flow cytometry in 9 cases showed expression of myeloid antigens (CD13 , CD33); 6 cases also expressed CD34 antigen. Significant dysplasia in volving erythroid and megakaryocytic lineages was seen in most of the cases. Trilineage dysplasia was observed in 5 cases. Median survival o f the entire group was 10.5 months. Eleven patients underwent inductio n therapy, consisting of daunorubicin and cytosine arabinoside +/- 6 t hioguanine; 8 patients achieved complete remission (72.6%). Remission duration was 14.5 months. Three patients (27.4%) died secondary to inf ections during induction therapy. Higher frequencies of trilineage dys plasia and FAB M6 type together with low percentage of peripheral blas ts and presence of antecedent hematologic disorders suggest that some of these cases might represent the hypocellular form of acute myeloid leukemia with trilineage dysplasia.