CHAPTER 12 



LYMPHOCYTES OF THE 

 LYMPHOCYTIC LEUKEMIAS 



MAURICE N. RICHTER 



This chapter is limited to certain aspects of the cells and lesions found in 

 leukemia and related states, especially the relations of cell types, tissue 

 changes, and clinical course. 



Neoplastic conditions involving lymphocytes occur in forms which at 

 one extreme are localized to certain regions and at the other extreme are 

 widely disseminated, involving many, or seemingly all, lymphatic tissues. 

 The presence of intermediate and transition forms raises questions of prob- 

 able relationships and reasons for the differences in distribution. 



CELL TYPES 



Similarly, the cell types of tumors may be morphologically typical of some 

 stage in the normal development of the lymphocyte or may deviate there- 

 from by having nuclear or cytoplasmic abnormalities not found in normal 

 lymphopoiesis. Although tumors arising from so-called reticulum cells or 

 histiocytes are not lymphatic tumors, they must be discussed because of the 

 possible relationships of their cells of origin. 



Certain general statements, to which there are numerous exceptions, may 

 be made: 



1. In general, tumors that apparently arise in individual lymph nodes 

 or node groups tend to spread by metastatic deposits of more or less focal 

 (localized, nodular) character, often in regional areas at first, in much the 

 same way that metastases from other types of tumor occur. 



Exceptions: In some cases the rapid dissemination of cells by the blood 

 stream obscures the sequence of events, leads to diffuse involvement, and 

 raises the question of possible multiplicity of foci of origin. 



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