THERE have been many observations in medical literature in which megakaryocytes have been described as a prominent feature in pathologic conditions of the blood. The number of these cells is frequently increased in thrombocytothemia and polycythemia vera. Their presence in the bone marrow, liver, spleen and other viscera has been mentioned in numerous articles on myelogenous leukemia and various other diseases. Although the classification of leukemias by most American authors, including Bethell,1 Downey,2 Forkner,3 Kolmer,4 Kracke,5 Osgood,6 Levin7 and Wintrobe,8 recognizes the possibility of megakaryocytic leukemia, the specific criteria necessary for such a diagnosis are not stated in detail.
Von Boros and Korényi9 reported a condition in 1931 which they designated as "acute megakaryoblastic leukemia," but the authenticity of the case has been questioned by American hematologists owing to lack of sufficient data.
Lindeboom10 in 1938 noted that giant cells of megakaryocytic type were prominent features in a group of