LYMPHADENOSIS AND LEUKAEMIA 347 



of growth : it is the cell that has normal relationships that is 

 most apt to attain and to retain complete differentiation. 

 Hyperplasia connotes cell proliferation, and where two cells 

 take and retain the place of one, ODe, if not both, of those cells 

 must fail to preserve the normal relationship to nutrient vessel, 

 stroma, etc. Hyperplasia thus favours anaplasia of at least a 

 portion of the cell elements of the affected part. Thus we find 

 that a portion of or all the cells of a gliosis may take on a more 

 sarcomatous type (I use the term here strictly in a histological 

 sense) ; areas of a liposis (e.g. of a retroperitoneal " lipoma ") 

 or of a leiomyosis may become sarcomatous ; and as regards the 

 myeloses and lymphadenoses, we observe a very interesting set 

 of conditions. 



The so-called multiple myeloma, for example, has all the 

 features of a hyperblastosis — excessive development occurring 

 in certain bones only, and absence of limitation save by the 

 natural boundaries of the involved areas — with this in addition, 

 that the constituent cells are of " embrvonic " character, so 

 embryonic that here and there they are liable to exhibit active 

 malignancy, and may not merely absorb the bony trabeculae 

 but may infiltrate the periosteum and surrounding tissues, and 

 even, if rarely, may give rise to metastases in other organs at 

 a distance, or to quote Berlinger, " myeloma is becoming to an 

 increasing extent regarded as a systemic disease of a malignant 

 type." So vegetative is the type of cell in many of these cases 

 that, as well known, there is active debate regarding their origin, 

 whether they belong to the lymphoblastic or to the myeloblastic 

 type. The indications appear to be more and more convincing 

 that there may be a specific hyperblastosis involving each distinct 

 element of the bone marrow — the lymphoblasts, the myeloblasts, 

 and the erythroblasts (as in Bibbert's well-known case of megalo- 

 blastic overgrowth which he held to be an erythroblastoma 

 (more accurately an erythroblastomatosis). 



Of peculiar interest in this connexion are the more recent 

 observations upon Chloroma. Here there are the same regional 

 ill-defined overgrowths most often occurring in early fife, and 

 involving particularly the skull, ribs, or sternum. Constantly 

 where the blood has been examined, the picture has been that of 

 leukaemia, with predominance of the large or relatively large 

 non-granular mononuclear cell, although in a small proportion 



