Morphometric study of megakaryocytes size and prognosis in adults with acute non-lymphocytic leukemia.

Morphometric analysis of megakaryocyte cellular and nuclear size in bone marrow biopsies of 28 cases of acute non-lymphocytic leukemia at diagnosis and 15 controls was performed. Median megakaryocyte cell diameter, median area, and perimeter were less than 95% control range (less than 18.5 microns, less than 263 microns2, less than 64 microns) in 5/5 of induction failures. Attainment of complete remission was significantly greater in those with median megakaryocyte diameter greater than or equal to 18.5 microns (p less than 0.01), median area greater than or equal to 263 microns (p less than 0.001) and perimeter greater than or equal to 64 microns (p less than 0.001). Prolonged complete remission was correlated with normal megakaryocyte size with the median megakaryocyte area, median diameter, and perimeter within or greater than the reference range (greater than or equal to 18.5 microns, greater than or equal to 263 microns2, greater than or equal to 64 microns, p less than 0.05) in 6/7 cases with continuous remissions greater than 3 yr. Measurements of megakaryocyte size may be useful in predicting induction failure and possibly the likelihood of prolonged complete remission in adults.