40 MASS. EXPERIMENT STATION BULLETIN 391 



particularly common about the duodenum and pancreas and ileocecal ligaments. 

 The smaller nodules of tumor on the oviduct and serosa were composed principally 

 of epithelial elements, varying in different sites from undifferentiated carcinoma 

 cells to fairly well organized glandular structures. Another element of the 

 smaller nodules was compressed spindle-shaped cells. The majority of these 

 spindle-shaped cells gave the chemical reaction of connective tissue with the 

 Van Gieson method. Scattered throughout and intermingled with the connec- 

 tive tissue fibers were a few cells which had the distinctive yellow color of muscle 

 cells. 



4. S 253. A hen, 27 months old, was killed for examination because of a large 

 pendulous abdomen. The enlargement of the abdomen was found to be due to 

 the accumulation of approximately 800 ml. of ascitic fluid. Numerous small, 

 firm nodules were scattered on the visceral peritoneum (Plate XII, Figure 1). 

 The ovary was represented by an irregular mass of firm nodules. The tumors on 

 the peritoneum and the ovarian tumor were found to be made up of both epithelial 

 acini and connective tissue cells, among which were scattered a few cells with the 

 tinctoral properties of muscle tissue. A leiomyoma, 20,mm. in diameter, composed 

 of muscle cells only was found in the mesosalpinx. 



5. S 36. A 26-month-old hen was killed for examination because of general 

 symptoms of debility. A marked ascites was found. The mesentery was covered 

 with nodular, firm, gray-white tissue and the o\ary was represented by a mass 

 of similar tissue. The neoplasm consisted of epithelial cells forming small im- 

 perfect acini supported by a framework of compressed spindle-shaped connective 

 tissue cells, among which were scattered small irregular collections of smooth 

 muscle cells. 



6. Q 1621. The hen died at the age of 55 months. The carcass was emaciated . 

 An irregular tumor mass of the mesentery and thickening of the wall of the in- 

 testine had caused an almost complete obstruction to the lumen of the duodenum. 

 The ovary was involved with a similar tissue and measured approximateh' 

 50 X 45 X 30 mm. The neoplasm was made up of carcinoma cells forming irreg- 

 ular tubules and acini, connective tissue cells, and a few smooth muscle cells 

 (Plate XII, Figure 3). 



7. Case 922. A 31 -month-old hen with a distended abdomen was killed for 

 examination. A marked ascites was present. Two multilocular cysts were found 

 in the abdominal cavity, which seemed to be attached to the mesentery. Many 

 small, firm nodules were scattered on the serosa of the viscera. Both adrenals 

 were enlarged and infiltrated with gray tissue. The tumor consisted of a mixture 

 of adenocarcinoma and spindle-celled sarcoma tissue. Van Gieson's preparations 

 indicated scattered collections of muscle cells among sarcoma cells of the con- 

 nective tissue framework. This case has been previously described (23), and at 

 that time the possibility that the tumor had arisen from displaced embryonic 

 mesonephric tissue was considered. The character of the tumor and the involve- 

 ment of the adrenals cause the case to be different from the other carcinosarcomas 

 described above. 



Information on egg production was available on five cf the cases of carcino- 

 sarcoma. The data are listed in Table 18. The hens were good producers, the 

 average index of production being 0.575 which is higher than the index of 0.534 

 for the flock from which these birds were derived. 



All of t*he birds affected with carcinosarcoma were of advanced age, ranging 

 from approximately 78 to 220 weeks at the time of examination, and averaging 

 about 115 weeks in age. As a group they are the oldest represented among the 

 various forms of neoplasia. The next oldest group was those birds affected with 

 carcinoma, with an average age of 75.5 weeks. 



These tumors which have been grouped as carcinosarcomas may be regarded 

 as an entity for the purpose of classification. A feature common to all the cases 

 was the widespread implantation of the mixed tumors on the serosal covering of 

 the viscera, as well as the marked proliferative activity of the sarcomatous ele- 

 ments. The ovary, pancreas, and adrenal were the only visceral organs affected 

 by the tumor and it would appear that the epithelial elements of the tumor must 

 have been derived from these organs. In three cases the ovary alone was affected 



