Acute myelofibrosis terminating in an acute lymphoblastic leukemia: a case report.

A patient with acute myelofibrosis developed acute leukemia during the course of her disease. Light microscopic examination showed that the cells were lymphoblasts. The presence of terminal deoxynucleotidyl transferase and T- and B-lymphocyte markers suggested that the malignancy was of immature lymphoid cell origin. Terminal leukemic transformation in some cases of acute myelofibrosis may be of a lymphoid nature and, thus, less toxic chemotherapy could be used with a better prognosis.