390 THE BLOOD AND THE BLOOD-FORMING ORGANS. 



which usually fills the shafts of the long bones with a firm, pink mass 

 composed largely of myelocytes. This hyperplasia may involve the 

 whole bone marrow of all the long bones, or it may be confined to irregu- 

 lar, scattered areas, so that one should be critical ill accepting reports of 

 cases of leukaemia without bone-marrow changes. The other organs show 

 hyperplasia of lymphoid tissue, often especially well marked in the 

 gastro- intestinal tract, while scattered through the spleen are often seen 

 numerous small areas containing myelocytes. 



There is some reason to think that in the spleen, for instance, some 

 multiplication of the cells goes on in the so-called "marrow cell or 

 myeloid metastases." The same change may rarely be seen in the liver 

 and lymph-nodes. In the blood, spleen, and marro\v, after death, elon- 

 gated octahedral crystals (called Charcot-Leyden crystals) are occasion- 

 ally found. Haemorrhages into the serous and mucous membranes and 

 the retina are quite frequent, especially the latter, and fatty degeneration 

 of the viscera is a quite constant expression of the impoverished condi- 

 tion of the blood. For more detail concerning the lesions of the organs, 

 see chapters on spleen, lymph-nodes, bones, etc. 



PSEUDO-LEUKJEMIA. (" Hodgkin's Disease," " Adenie.") 



Under this term it has been customary to describe a rather hetero- 

 geneous group of cases characterized by progressive anaemia, by hyper- 

 plasia of the lymph-nodes and nodules, with an occasional but by no 

 means constant involvement of the spleen, liver, and bone marrow, and 

 by new growths of lymphatic tissues in many parts of the body. While 

 anaemia of moderate or severe grade is very constantly present in 

 this disease, the increase of leucocytes characteristic of leukaemia is 

 wanting. 



Of the exact nature of the disease (if it be a single disease) very little 

 is definitely known. The enlargement of the lymph-nodes is in typical 

 cases due to simple hyperplasia. The blood changes may present the 

 type of pernicious anaemia, and in well-authenticated cases the condition 

 has developed into true leukaemia. Recent evidence favors the belief that 

 some cases classed under this heading may be of an infectious character, ' 

 one of the most frequently observed agents being the tubercle bacillus. 

 Cases of primary sarcoma of the lymph-nodes have been described as 

 cases of pseudo-leukaemia. 



The condition found at autopsy varies greatly according to the distri- 

 bution and character of the new growths of lymphatic tissue. The lym- 

 phatic nodules involved may be principally limited to the subcutaneous 

 connective tissue (dermal type). Or the lymph-nodes of the pharynx 

 and neck may be chiefly involved (tousillar type). Or the axillary or 

 inguinal or mediastiual or retroperitoueal groups may be involved. A 



1 Flexner, "Multiple Lympho-sarcomata," Johns Hopkins Hospital Reports, vol. 

 iii., p. 153; also I^ongcope. Bulletin of the Ayer Clinical Laboratory of the Pennsyl- 

 vania Hospital, No. 1, 1903, p. 4. 



