The Roentgen Treatment of Leukemias

Abstract

BY leukemia is meant a condition in which there is extensive proliferation of the leukopoietic tissues of the body, either lymphadenoid or myeloid, with the appearance in the blood of white blood cells not normally present. There is, usually, an increase in the number of white cells; this, however, is not the absolute rule. In 1845, Virchow recognized the leukemic states at the autopsy table: shortly afterward Vogel recognized the disease during life. Since the work of these pioneers our ideas of the leukemias have undergone remarkable development. During the past years we have learned to distinguish between leukocytosis and leukemia. This differentiation has not been made on the number of white cells present, as there are often cases with a leukocytosis of 100,000 white cells per c.mm. and leukemias showing only 50,000 white cells. The usual leukemia as a rule shows a white count far in excess of 50,000. Another important step in the diagnosis of leukemia was the recognition of the qualitative deviations in the white cells, which was of far greater aid in differentiation than the quantitative changes in the total count. Ehrlich, by means of specially stained smears, introduced the differential blood count, which was an important factor in diagnosing these difficult blood diseases. It was soon found that in certain cases of leukemia the lymphoid cells predominated, while in others the myeloid cells were more common. Following this discovery it was thought for a time that the presence of myelocytes was absolute evidence of leukemia; later on, the non-leukemic myelocytes of bone marrow carcinosis and anemia pseudoleukernica infantum were recognized. Through clinical and autopsy studies, it has been demonstrated that proliferation of either the lymphoid or myeloid tissues similar to those that occur in the leukemias may take place without the appearance of immature cells in the blood. In the majority of cases, a diagnosis can be made from the differential count of the white cells alone; in some cases, however, the blood picture in itself is insufficient for a diagnosis. In arriving at a diagnosis no one method or sign should be depended upon as conclusive. Each patient should be studied by all available methods before drawing our final conelusion. It was thought by some, on account of the enlarged spleen in some cases of leukemia, that leukemia is splenogenous in origin; this we know is not true and that the leukemias are divided into two main groups, namely, those of lymphadenoid origin and those of myeloid origin. Leukemia is not a disease of anyone organ, but a condition that is widespread throughout the body. In certain patients, the disease may attack the lymphadenoid tissues all through the body, while in others the disease may show a predilection for the myeloid tissues of the marrow of the various bones of the body.