2/6 CLINICAL BACTERIOLOGY AND ELEMATOLOGY 



LYMPHATIC LEUCOCYTHAEMIA. There is no difficulty in the 

 recognition of a typical case of chronic lymphatic leucocy- 

 thaemia; the leucocytes are enormously increased (100,000 to 

 1,000,000), and consist almost entirely of lymphocytes (often 

 up to 99 per cent.) : in many cases the large forms predomin- 

 ate. There is also a varying degree of secondary anaemia. 



In an adult these appearances are quite characteristic, but 

 in childhood similar counts may be seen in a variety of condi- 

 tions, such as hooping-cough, broncho-pneumonia, etc., 

 though it is rare to find a figure as high as 100,000. 



In some acute cases of lymphatic leucocythaemia similar 

 appearances occur. In others the increased percentage of 

 lymphocytes is present, but not the total increase; thus, in 

 one case fatal in a few weeks I never found more than 10,000 

 leucocytes (in which the lymphocytes varied between 76 

 per cent, and 100 per cent.). These cases are very difficult to 

 diagnose from acute tuberculosis of the lymphatic glands. 

 In the latter case the total count may be expected to be low, 

 in the former slightly raised; in tubercle the percentage of 

 lymphocytes rarely exceeds 50, whilst 75 per cent, at least 

 would be required before the condition under discussion 

 could be diagnosed. 



Other diseases (especially acute purpura haemorrhagica) 

 give very high lymphocytoses in adults, but as they are 

 quite different clinically, the blood-count would not be 

 misleading. 



HODGKIN'S DISEASE. There is little doubt that several 

 diseases are included under this heading. In the true Hodg- 

 kin's disease there is at first no change in the blood, not even 

 anaemia; in one case I examined at intervals for over a year 

 the red corpuscles were always above 5,000,000, and the 

 haemoglobin above 100 per cent. Later, there is anaemia of 

 secondary type, with a slight leucocytosis, with or without a 

 moderate increase of polynuclears. In others cases there 

 may be anaemia from the first, a normal or diminished num- 

 ber of leucocytes, and a relative increase of lymphocytes of 

 moderate amount; these cases are probably more closely 

 allied to lymphatic leucocythaemia, and for them the term 

 " pseudoleukaemia " might be used. I believe them to be of 

 more rapid course than true Hodgkin's, but the two cannot 

 be definitely separated on clinical grounds alone. 



