CHAPTER XXXII. 

 CYTODIAGNOSIS. 



THIS method of diagnosis is chiefly employed in the examination of 

 cellular sediments of pleural, ascitic and cerebrospinal fluid. 



For pleural fluids we should receive the material in centrifuge tubes 

 about one-fourth filled with 2% sodium citrate salt solution. This 

 prevents clotting. Having thrown down the sediment, the superna- 

 tant fluid is poured off, and in its place a i% aqueous solution of 

 formalin is added. After mixing and allowing to stand for about five 

 minutes, centrifugalization is again repeated and, pouring off the 

 supernatant formalin solution, we make smears from the sediment. 

 This is either stained by a Romanowsky method or, after fixing with 

 heat (burning alcohol), the smear is stained with haematoxylin and 

 eosin. 



At the time of securing fluid for cytodiagnosis, cultures should be 

 made on blood-serum for various pyoqjenic bacteria and, if tuberculosis 

 is suspected, inoculation of a guinea-pig is indicated. 



The interpretation of cellular sediments is more difficult than many 

 books would indicate, there being many factors which tend to com- 

 plicate the findings. The following are the leading differentiations: 



1. A smear showing almost entirely lymphocytes with a few red 

 cells and very rarely a polymorphonuclear indicates a tubercular 

 process. 



2. Where a pyogenic process is engrafted on a tuberculous one, we 

 have still the red cells, some degenerated lymphocytes and in particular 

 polymorphonuclears showing fragmentation of their nuclei. 



3. When a hydrothorax results from chronic heart or kidney 

 disease, the characteristic cell is the endothelial cell, which greatly 

 resembles a large mononuclear. 



4. Some authorities consider that the cancer cell can be recognized 

 by its occurring in masses and having a markedly vacuolated cytoplasm. 



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