348 ON GROWTH AND OVERGROWTH 



of cases there have been granular mononuclears. The picture 

 has been that of either acute lymphatic or acute myelogenous 

 leukaemia. By the employment of the oxidase (indophenol) 

 test, 1 which differentiates between lymphocytes and myelocytes, 

 my colleague, Professor Burgess, has demonstrated clearly that 

 the marrow growths and the characteristic blood cells in this 

 condition are myelogenous, not lymphogenous. The condition 

 is a myelomatosis, or, to use ordinary terminology, an " acute 

 myelogenous leukaemia," and confirming Schultze, Longcope and 

 Cooke, and others, Burgess points out that cases of so-called 

 acute lymphatic leukaemia with " large lymphocytes " are truly 

 cases of acute myelogenous leukaemia (or strictly of acute myelo- 

 matosis with leukaemia). 2 



Parallel to these conditions affecting the bone marrow of 

 particular localities with their liability to malignancy, we may 

 cite the not infrequent mediastinal tumour, which originating 

 in the thymus (and perhaps sometimes in the mediastinal lymph 

 nodes) shows a striking liability to become locally malignant, 

 infiltrating all the surrounding tissues. 



From these intermediate forms we pass on by imperceptible 

 gradations to cases of primary malignant hyperblastosis, to cases 

 of diffuse lymphosarcomatosis and myelosarcomatosis. 



If the views here laid down and the relationships of this 

 group of conditions be correct, we arrive at certain interesting 

 conclusions. Namely, and first, that whatever be the essential 

 cause of the autonomous blastomas, we have in these hyper- 

 blastoses a group of diffuse overgrowths which by analogy must 

 be regarded as due to disturbances of metabolic equilibrium ; 

 which, further, in their simple non-malignant stages at least, 

 may possibly be combated eventually (certainly not to-day) 

 along the lines of organotherapy. Secondly, that every transition 

 is observable in this series between the development of over- 

 growths of fully-differentiated tissue, non-malignant grades of 

 anaplasia, and diffuse malignant infiltrative growths. This 



1 Burgess, Journ. of Med. Research, xxvii., 1912, 133. 



2 I must, however, disagree with my colleague in regarding leukaemia as 

 a blood metastasis. The symptom leukaemia is not an index of malignancy ; 

 the discharge of leucocytes into the blood is not of the nature of a malignant 

 infiltration ; on the contrary, it is best regarded as the outcome of chemiotactic 

 phenomena, as an attraction of marrow cells by something circulating in the 

 blood. There may be extensive lymphadenosis or myelosis without leukaemia, 

 or leukaemia may be present for a time, and then disappear — and reappear. 



