Hypocellular acute myeloid leukemia in adults: Analysis of the clinical outcome of 123 patients

Background: The hypocellular variant of acute myeloid leukemia accounts for less than 10% of all cases of adult acute myeloid leukemia. It is defined by having less than 20 percent of cellular bone marrow in a biopsy at presentation. It is unclear in the literature whether the outcome of hypocel-lular acute myeloid leukemia differs from that of non-hypocellular acute myeloid leukemia. Design and Methods: We retrospectively analyzed all the cases reported to be hypocellular acute myeloid leukemia between 2000 and 2009. A second pathology review was conducted and the diagnosis was confirmed in all cases. Results: One hundred twenty-three (9%) patients were identified: patients with hypocellular acute myeloid leukemia were older than those with non-hypocellular acute myeloid leukemia (P=0.009) and more frequently presented with cytopenias (P<0.001). Forty-one patients with hypocellular acute myeloid leukemia had an antecedent hematologic disorder and 11 patients had received prior chemo-radiotherapy for non-hematopoietic neoplasms. On multivariate analysis, overall survival, remission duration and event-free survival were comparable to those of other patients with acute myeloid leukemia. Conclusions: The outcome of hypocellular acute myeloid leukemia does not differ from that of non-hypocel-lular acute myeloid leukemia.