30 MASS. EXPERIMENT STATION BULLETIN 391 



Data on egg production were available on onl\ three of the eases. The bird 

 of case T 74, afTected with carcinoma of the o\ar\-, laid 518 eggs in 1244 da\'s 

 of production. Her production index was 0.416 or slightly below the average 

 of the flock. Her last egg was laid 116 days before necrops\-. The hen of Case 

 758 laid 720 eggs in 1600 days of production for a production index of 0.450, 

 also slighth' below average. The last egg was laid 205 days before necropsy. 

 The bird affected with papillary cystadenoma of the gizzard (case T 130) laid 235 

 eggs in 363 days of production. The production index of 0.648 was rel.\tivel>' 

 high. Her last egg was laid 54 days before necrops\ . 



Hepatoma 



Small hepatomas were noted in the livers of three chickens as a finding incidental 

 to other unrelated pathology. These islands of slowK proliferating liver cells 

 were regarded as neoplastic because of their solitary occurrence and because of 

 lack of evidence for liver damage that might have stimulated focal regeneration 

 of the liver. 



1. T 210. A 53^-month-old pullet died showing acute focal necrosis of the 

 liver. A pendunculated nodular mass measuring 25 X 20 X 15 mm. was found 

 attached by a broad base 15 mm. in diameter to the visceral aspect of the left lobe 

 of the liver. The mass was darker than the liver and somewhat hemorrhagic. 



2. T 301. A 7-month-old pullet suspected of pullorum disease was killed 

 for exan;ination. A firm, rounded tumor mass approximately 2.5 cm. in diam- 

 eter was found near the surface of the left lobe of the liver. 



3. Case 438. A 5-month-old pullet was killed for examination because of 

 symptoms of fowl paralysis. LIpon necropsy a gray-white nodular mass 18 mm. 

 in diameter was found in the mid portion of the right liver lobe. Lesions of fowl 

 paralysis were present. 



The histologx- of all three cases of hepatoma was similar (Plate XI, Figure 1). 

 The neoplastic liver cells closely resembled normal Vwer cells. The arrangement 

 of the cells varied in different portions of the tumor. In some areas they were 

 without definite arrangement; in other areas they formed distinct cords, parallel 

 to an empty channel re.sembling a liver sinusoid. The liver substance adjacent 

 to the hepatoma was compressed and not infiltrated by the tumor. 



From these data hepatoma of the chicken appears to be a rather uncommon 

 neoplasm. Its benign character is indicated by the fact that all of the cases were 

 incidental findings. 



Cholangioma 



The diagnosis of cholangioma or adenoma of the bile duct was a problem m 

 several cases. The difficult}- arose because of the marked connective tissue and 

 polyblastic response that occurred in many of the cases diagnosed as cholangioma. 

 Instances of cirrhosis, hepatitis, and cholangitis were seen in which there was an 

 active fibrosis in the periportal areas coupled with a proliferation of the bile 

 ducts. In some, the proliferation was so extensive as to suggest a neoplastic 

 state. One case of a fibrosarcoma of the liver is described in another section with 

 a similar reaction of the bile ducts. The basis upon which a pathologist may 

 separate a neoplastic from a granuloblastic process is rather arbitrary under such 

 conditions. It is, of course, "possible that the neoplastic condition might arise 

 from a process that in the beginning was only a granuloma. Except for the 

 reports of Goss (11) and Eber and Malke (4), biliary carcinoma of the chicken is 

 not often discussed in the literature. Unfortunately no description is given of 

 the cases mentioned in these reports. It is worth while, therefore, to present a brief 

 description of the four cases of cholangioma found in this collection. 



