Recently Lucas1 in an exhaustive article on erythremia reviewed the literature in a comprehensive manner, adding two new cases to the series. It is apparent that a greater number of cases of polycythemia with chronic cyanosis and with or without splenomegaly are being recognized.
Among the various theories advanced as to the cause of erythremia, the one originally suggested by Rendu and Widal,2 and later amplified by Osler3 and Weber,4 ascribes the changes that take place to unusual erythropoietic activities. Pathological findings have, in a measure, substantiated this explanation, though Saundby and Russell5 describe normal bone marrow findings in their case. If we are to accept this view of primary excessive formation of red cells in the bone marrow, we have an analogy to myelogenous leukemia, in which the leukoblastic activity dominates the picture. In contrast stands this notable feature of erythrmia—the absence of erythroblasts