90 SPECIAL DISEASES OF THE BLOOD 



usually contains an excessive number of leucocytes, a large pro- 

 portion of which (85-99%) are small lymphocytes. The red 

 corpuscles are diminished. Cabot found an average of 3,170,000 

 per cmm. and 40% hemoglobin in 16 cases in man. In the acute 

 cases the red corpuscles are usually much diminished, often less 

 than 1,000,000 per cmm. during the last days. Normoblasts are 

 usually present in much smaller numbers than in mixed-celled 

 leukemia and are sometimes absent even with very low red counts. 



The leucocytes are increased, though not so much, as a rule, 

 as in mixed-celled leukemia. Cabot found an average of 240,000 

 leucocytes (maximum, 1,480,000, minimum, 30,000) in 16 cases. 

 The majority of the leucocytes in chronic cases are small lym- 

 phocytes, 92-99%, average, 95% (Sternberg). Other varieties of 

 leucocytes are relatively scarce; occasionally myelocytes are found 

 in small numbers. In acute cases the predominating cell is a very 

 large lymphocyte with rather pale nucleus; in other cases varying 

 proportions of small, medium and large lymphocytes are found. 

 In acute cases the large cells are more abundant. In lymphatic 

 leukemia, degenerative changes may be found in the lymphocytes. 

 It is not uncommon to find small lymphocytes with cell bodies so 

 small as to be seen with difficulty. 



Pathological anatomy and histology. The pathological changes 

 found are in general very similar to those occurring in mixed- 

 celled leukemia. There is hyperplasia of the bone marrow, spleen 

 and lymph glands and growths or collections of cells in various 

 organs. Not infrequently hemorrhages occur in the central nervous 

 system, the subdural spaces and also in the several internal organs. 

 Hemorrhages are more common in acute cases. 



The bone marrow is involved in all cases in which it has been 

 examined (Pappenheim). It is rich in cells and in blood. The 

 cells are mainly lymphocytes. Large non-granular mononuclear 

 cells, finely granular and eosinophilic myelocytes, polymorphonu- 

 clear leucocytes and erythroblasts are present in small numbers. 



The spleen is usually much enlarged. Sometimes it is very cellu- 

 lar, but follicles and pulp cords are generally clearly distinguish- 

 able. The follicles are composed almost exclusively of small lym- 

 phocytes; large non-granular mononuclear cells occur in small 

 numbers and :i few finely granular and eosinophilic myelocytes 

 arc sometimes found. The trabecular arc not much increased in 



