THE LIVER. 



613 



carcinomata. These may be primary or secondary, and present the usual 

 structural variations. The cells may be cylindrical, or polyhedral; or 

 they may present the characteristics of gelatinous cancer. Primary carci- 

 nomata and adenocarcinoma of the gall bladder and larger gall ducts are- 

 not uncommon, and are frequently associated with calculi. 1 Not infre- 

 quently the pancreatic and common ducts are both involved, and it is 

 difficult to say whether the tumor is primary in the head of the pancreas 

 or in the gall duct. The bladder and ducts may also be secondarily in- 



FIG. 374. ADENOMA OF THE GALL DUCT. 



This section is from a small tumor growing within one of the larger gall ducts in the liver. 



volved in carcinomata of the stomach, liver, and duodenum. Adenoma 

 of the gall ducts is of occasional occurrence (Fig. 374). 



BILIARY CALCULI. (Cholelithiasis.) 



These bodies are of common occurrence. They are found usually in 

 the gall bladder, sometimes in the hepatic, cystic, and common ducts ; 

 less frequently in the small ducts of the liver. In the gall bladder from 

 1 to 7,800 calculi have been counted. They vary in size from that of a 

 pin's head to that of a hen's egg, or they may be larger. Single gall 

 stones are usually spheroidal or ovoidal ; when multiple they are usually 

 flattened at the sides or faceted (Fig. 375). 



They may be composed : 



1. Principally of cholesterin, and may be of pure white color, or 



'See Warthin, Philadelphia Med. Journal, vol. vi., pp. 38, 82, and 120, 1900, bib- 

 liography. 



