366 LEUKEMIA 



in typhoid, pneumonia, and peritonitis. — Ed. J. After the injection of an 

 agent causing leukocytosis, he followed step by step the changes in the bone- 

 marrow. As soon as the leukocytes appeared in the blood in large numbers, 

 the granular, mature elements in the bone-marrow almost wholly disappeared, 

 and, instead of these, in a few days, the immature forms, especially the 

 myelocytes, increased. The latter, therefore, covered the loss due to the 

 enormous emigration of the polynuclears into the blood as a result of the 

 leukocytosis. The spleen and the lymph-glands, however, in Rubinstein's 

 experiments, took no part in making up the loss of white corpuscles in poly- 

 nuclear leukocytosis, but, according to our present opinion regarding the 

 separate development of leukocytes and lymphocytes, this is not to be won- 

 dered at. 



From what has been stated, it is clear that the diagnosis of leukocytosis rests 

 primarily on the discovery of a disease which is recognized as usually giving 

 rise to leukocytosis. The diagnosis becomes more certain if the increase of the 

 white blood cells is a transitory one (i. e., disappearing with the cessation 

 of the underlying affection), and remains from the onset within moderate 

 limits. AVhile in leukemia ratios of 1 white to 10 red corpuscles, and even 

 1 to 2, are quite usual, in leukocytosis there is a much slighter relative in- 

 crease of leukocytes, and only in exceptional cases, as in cachectic conditions 

 when there is a decided decrease of the erythrocytes simultaneously with 

 leukocytosis, does it happen that proportional figures of 1 to 20 are observed 

 for a long time. Under such conditions these cases may simulate leukemia, 

 but here the recognition of morphological alterations in the white blood- 

 corpuscles leads to the correct diagnosis, because the excessive appearance 

 of myelocytes, eosinophiles, and mast-cells in the circulating blood (in short, 

 a markedly polymorphous condition of the blood elements which is quite 

 foreign to leukocytosis) directly favors the existence of leukemia. The diag- 

 nosis of the latter disease is also aided by the decided enlargement of the 

 spleen and lymph-glands, and the absolute and relative increase of uric acid 

 excretion in the urine, etc. 



These last named factors especially must be taken into consideration when 

 we are dealing with a lymphocytosis, because here the most important point 

 of distinction between leukemia and (polynuclear) leukocytosis, the poly- 

 morphia of the blood cells, is of no avail. In practice, however, the diagnosis 

 of lymphocytosis is never doubtful, the difficulty in differentiating between a 

 lymphocytosis and a feebly developed lymphocytic leukemia being theoretic 

 rather than actual. [On the contrary, mistakes have actually occurred. See 

 Steven (Lancet, 1902, vol. xx) and Cabot ("Clinical Examination of the 

 Blood," 5th edition, 1904, p. 194).— Ed.]. For, in the acute form of lympho- 

 cytic leukemia, the large lymphocytes almost always predominate, and this 

 alone is sufficient to prevent confusion between lymphocytic leukemia and 

 lymphocytosis; even in chronic lymphocytic leukemia the large lymphocytes 

 are not entirely absent in the microscopical preparations, although, in the 

 great majority of cases, only small leukocytes are found. 



Above all, the usually enormous increase of lymphocytes in lymphocytic 

 leukemia, the progressive, pernicious nature of the disease compared with the 



