PATHOLOGICAL HISTOLOGY 167 



We have not succeeded in demonstrating rickettsia in the 

 spleen to our own satisfaction. They may be present in cells 

 lining the splenic veins (sinuses) but other granules render their 

 recognition uncertain. 



(e) The liver: In no case were lesions of large blood vessels 

 found in the liver. An increase of cells in some portal spaces 

 is common. These cells may fill and distend the space. They 

 consist largely of lymphoid and plasma cells, though mono- 

 nuclear phagocytic cells are numerous. This reaction seems 

 to be a diffuse infiltration about small vessels rather than the 

 " typical nodules " described by Fraenkel and Ceelen in livers. 

 We have been unable to find thrombi in vessels in the portal 

 spaces. The central veins (hepatic veins) show no reaction. 



The most striking histological finding in the liver, described 

 by Aschoff, Ceelen, Nicol, and others, and which we find to 

 be practically constant, is a diffuse reaction on the part of the 

 endothelial lining of the sinusoids the Kupfer cells. These 

 cells are in large number, swollen, occasionally in mitosis and 

 very often with inclusions of red blood cells, leucocytes, pig- 

 ment, and detritus derived from nuclei. Rarely, blood plate- 

 lets can be recognized in these swollen, cells. Mononuclear 

 phagocytic cells, presumably detached Kupfer cells, are pres- 

 ent in varying abundance in the sinusoids of the livers from 

 all early cases. Patient search will usually also reveal a sinus- 

 oid filled with a fibrin thrombus and a rare degenerated or 

 completely necrotic liver cell. Mitoses in liver cells as well 

 as in the Kupfer cells are not rare. 



The type of inclusion in the Kupfer cell described by Kuc- 

 zynski (1918) as rickettsia from frozen sections does not ap- 

 pear to be present in our cases. Da Rocha-Lima's (1917, 

 1919, p. 297) failures to stain rickettsia in tissues is also 

 contrary to Kuczynski's demonstration of rickettsia in the 

 liver. 



Bodies consistent with the rickettsia observed by us in skin 

 vessel lesions and in lice sections are present in but small 

 numbers in Kupfer cells and therefore are of little confirma- 

 tory value. 



