34 MASS. EXPERIMENT STATION BULLETIN 391 



lesion in the liver of two of the cases might easily have been overlooked. It is 

 of interest to note that the liver was affected in four of the five cases studied, 

 which suggests a predilection of the liver of the chicken for development of 

 hemangioma. 



Lymphangioma 



Only one case of lymphangioma was encountered. A descripton of the case 

 follows. 



1. Case T 264. An 8-month-old, cross-bred female was sent to the lab- 

 oratory for examination. It was dead upon arri\'a), and the carcass was in poor 

 flesh. A considerable e.xcess of fluid was found in the peritoneal cavity, together 

 with fibrinous, yellow debris. Yellow debris and albuminous material were found 

 in the lumen of the oviduct. A tumor mass measuring 5X4X4 cm. was found 

 attached to the ovary by a long (5 cm.) narrow stalk. The tumor consisted of 

 soft, moist tissue, mottled gray and red in color. The more superficial part con- 

 tained many small cysts filled with clear fluid. Histologically the tumor was 

 composed of somewhat spindle-shaped cells with anastomosing cell processes. 

 In some areas they lined rather large spaces filled with faint pink staining material 

 (Plate XI, Figure 4). In other areas the}' exhibited a tendency to form small 

 capillary-like structures. The serous aspect of the tumor and some of the vis- ~ 

 ceral organs showed changes of a chronic fibrinous peritonitis. Illness and death 

 of the bird were probably due to the salpingitis and peritonitis, and the tumor 

 Avas an incidental finding disclosed only by necropsy of the bird. 



The histology of the tumor was very similar to that obser\ed in some of the 

 cases of hemangioma, except that no blood cells were found enclosed in spaces 

 formed b>- the neoplastic cells. 



Leiomyoma 



Thirty-four leiomyomas or tumors composed of smooth muscle cells were found. 

 They were firm, tough, and fibrous in consistency, and on cross section appeared 

 to be made up of interlacing bundles of tissue (Plate XII, Figure 5). The tumors 

 were usually somewhat encapsulated, were spherical or oval in shape, and varied 

 in size from a few millimeters to several centinieters in diameter. The largest 

 leiomyoma in the collection weighed 368 grams. 



The smooth muscle tumors were found onh' in female chickens. The most 

 common site for the tumor (27 cases) was the ventral ligament of the oviduct 

 at approximately the mid-portion (Plate XII, Figure 2). In five cases the tumor 

 was in the wall of the oviduct; in one case tumor was found in both the mes- 

 osalpinx and the oviduct ; and in one case the location could not be determined 

 as the specimen consisted of a tumor mass which had been "found in the abdom- 

 inal cavity of a hen." In only one case was there spread or metastasis of the tumor. 

 In this instance the primary tumor was in the ventral ligament of the oviduct 

 and metastatic foci of the tumor were found in the liver and breast muscle. 



Leiomyomas are classified according to the time of year they were observed, 

 as follows: first quarter, 6 cases; second quarter, 10 cases; third quarter, 13 cases; 

 and fourth quarter, 5 cases. The average age of birds with leionnoma was 61 

 weeks (range 26 to 107 weeks) for 15 birds that were killed for examination, and 

 71 weeks (range 37 to 106 weeks) for 19 birds that died. 



In practically all cases, the leiomyoma was an incidental finding at the time 

 of necropsy. In no instance was such a tumor reponsible for specific symptoms 

 of the disease. 



Egg production records were available on 18 of the birds affected with 

 leiomyoma. These data are given in Table 17 and indicate that the birds were 

 well above average in their ability to produce eggs. The average production 



