CHAPTER 15 



THE CHANGING PATTERN OF 

 LYMPHOCYTIC MALIGNANCIES 



R. PHILIP CUSTER 



Doctor Schwartz' chapter (Chapter 14) is a most beautiful and convincing 

 demonstration of cellular multipotentials. Not only does he show the de- 

 velopment of leukemic cells from indifferent reticular elements but from 

 differentiated cells as well, notably those of the renal capsule, which we 

 generally assume to be relatively inert fibrocytes. After Doctor Schwartz' pres- 

 entation I feel much better about my habitual use of the term "leukemic 

 metaplasia - ' in place of the conventional "leukemic infiltration." Leukemic 

 cells unquestionably can and do colonize from the peripheral blood, as 

 well as infiltrate, but I have long maintained that their interstitial growth 

 can likewise be autochthonous from preexisting elements, probably reticulo- 

 endothelial for the most part. 



In one of my earlier papers, 1 the following statement was made: "The 

 concept of the cell as a static unit must be discarded." This was based on 

 experience with a large number of cases of leukemia and lymphoma in 

 which tissue was sampled at various times during the course of the disease, 

 and autopsy material generally obtained. In collaboration with Dr. William 

 Bernhard, the results of our first analysis were published in 1948, 2 conform- 

 ing substantially to the flow diagram shown in Figure 15-1. In over 35 

 per cent of cases there was a significant change in the histologic character 

 of the malignant growth, an incidence confirmed recently by Doctor 

 Edward Gall. 3 



While the occurrence of such transitions has been commoner among 

 the lymphomatous disorders, they are by no means confined to this category. 

 Changes in the myeloproliferative group, coupled with malignant plasmo- 

 cytic disease, are shown in Figure 15-2, the latter merely representing geo- 



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