MYELOGENOUS LEUKEMIA. 167 



splenomyelogenous. It must be borne in mind, however, that while 

 a greater change in the lymphatic glands may produce the lymphatic 

 type, yet even in such cases we expect to find alteration in bone marrow 

 and spleen; that is, there is a general involvement of the haemopoietic 

 system in all leukaemias, the activity being most marked in spleen and 

 bone marrow in certain cases and in lymphatic glands in others. 



Myelogenous leukaemia is a very rare disease, about five times as 

 rare as pernicious anaemia. Lymphoid leukaemia is still more rare. 



Splenomyelogenous Leukaemia (myeloid leukaemia). The 

 differentiation of the blood picture of this disease from leukocytosis 



FIG. 54. Myelogenous leukaemia, m, Myelocyte; p, polymorphonuclear; 

 /, mast cell; n, normoblast. (Cabot.) 



does not depend on the number of leukocytes, but on the presence and 

 large proportion of myelocytes. We expect both neutrophilic and 

 eosinophilic myelocytes in myeloid leukaemia the proportion of these 

 varies, but, as a rule, the neutrophilic one is the common one. The 

 blood in advanced cases is milky and shows a most marked buffy coat. 

 The marrow is largely replaced by a yellow pyoid material. The 

 spleen may weigh ten pounds. The leukocyte count is on the average 

 from 200,000 to 500,000. Cases are recorded of more than one million 

 white cells. The neutrophilic myelocytes make up about thirty to 

 forty per cent, of these and, about equal in number, are found the 



