Histochemistry of Lymphocytic Tissue in Malignant Lymphomas 199 



activity in tumor histiocytes and Sternberg cells. Again, activity, although 

 definitely present, frequently appeared to be diminished as compared with 

 normal. The same case demonstrated acid phosphatase in Sternberg cells 

 and histiocytes. Leucine aminopeptidase was similarly shown in the same 

 instance. 



Examination of the typical proliferation of apparently mature lympho- 

 cytes in lymphocytic lymphoma in sections stained for esterase manifested 

 the crowding out of the positively stained histiocytes by the proliferating 

 lymphocytes. However, in several other instances, especially those from 

 chronic lymphocytic leukemia, the lymph node architecture remained almost 

 intact. Acid phosphatase activity (represented by minute, red cytoplasmic 

 granules) was typically seen in the lymphocytes of blood smears of chronic 

 lymphocytic leukemia. Sections illustrative of the typical nodular morphol- 

 ogy seen in follicular lymphoma were stained to demonstrate esterase. 

 Histiocytes were crowded out by the lymphocytes in the follicles but were 

 apparent in the compressed adjacent nodal tissue. 



METABOLIC ENZYMES IN LYMPHOID ELEMENTS 



Only preliminary work has been begun on the group of enzymes depicted 

 in Table 16-3, largely these concerned with intermediate metabolism. These 

 include succinic dehydrogenase, 9 monoamine oxidase, 10 DPN and TPN dia- 

 phorases, 9 adenosine triphosphatase, 11 glucose-6-phosphatase, 12 and phos- 

 phorylase. 13, 14 Note that lymphoid elements appear to be unreactive with 

 the last three. In general, lymphocytes seem to possess strong succinic de- 

 hydrogenase and DPN diaphorase, 1 especially in the spleen, while TPN 

 diaphorase and monoamine oxidase activities are weak. Activity of all four 

 enzymes is greater in histiocytes within lymph nodes but is probably less in 

 the spleen. More active cells, such as epithelioid cells, appear to have height- 

 ened activity of this group of enzymes. Thus far, in the only two cases of 

 lymphoma studied, the enzymes appeared to be present in the cells in 

 normal or slightly subnormal concentrations. No definitive statements are 

 as yet permissible on the basis of our data. 



CONCLUSION 



We have been able to identify lymphoid cells with reasonable certainty 

 using enzymatic techniques. Perhaps a wider use of these methods will take 

 some of the confusion out of the nomenclature of malignant lymphomas. 

 It is also hoped that we shall increase our knowledge concerning metabolic 

 derangements of the neoplastic cells in these conditions, 



