NEOPLASTIC DISEASES IN CHICKENS 25 



Three examples of this tumor were found. A brief description of each of these 

 cases follows: 



1. T 5. A 7-month-old pullet was killed for examination because of symptoms 

 of general debility. A tumor mass weighing 217 grams was found in the region 

 of the pancreas. Histological section revealed that although it did not actually 

 invade the pancreas this organ was markedly compressed by encircling growth 

 of the tumor. In some areas the tumor was distincth' fibroblastic in character. 

 In other areas the tumor was composed of large, round cells possessing a relatively ' 

 large vesicular nucleus with a large, distinct nucleolus. In still other areas the 

 arrangement was much less compact and the cells were stellate with anastomosing 

 cell processes. Areas of necrosis were found in the tumor with a polyblastic 

 reaction composed of lymphocytes, plasma cells, and granulocytes on the serous 

 surface of the tumor mass. A marked lymphoc\tic h\'perplasia was observed 

 in the liver, kidney, and proventriculus. Hyperplasia of the myeloid elements 

 of the bone marrow was present in which the development of granulocytes was 

 largely definitive. 



2. T 52. A somewhat emaciated hen, one year old, was killed by the owner 

 and submitted for examination. There was an e.xcess of cloudy, \'ellow peritoneal 

 fluid containing masses of rather dry, yellow debris. The visceral serosa was 

 distincth- thickened and the mesentery was shortened causing the intestinal 

 tract to be contracted into a small, firm mass from which it was impossible to 

 separate individual loops of intestine. The liver was enlarged and contained 

 numerous, variable-sized foci of white tissue the largest of which measured 1 cm. 

 in diameter. The centers of these foci were depressed giving them a crateri- 

 form appearance. Many of the masses were confluent and others had a sharp, 

 discrete border. The ovary appeared normal and non-functioning yet on section 

 a rather large mass of tumor was found replacing the parench\'ma. The tumor 

 covering the serosa and in the liver and ovary was variable in its histological 

 aspect and resembled that found in the case previously described. 



3. T 280. This case was a 7-month-oId pullet which was killed for examina- 

 tion. A moderate swelling was noted over the left pectoral region. The swelling 

 was found due to a tumor mass in the subcutis overlying the left breast muscle 

 and extending the length of the sternum. The tumor tissue was gray-\ellow in 

 color and enclosed cavities some of which were filled with dark brown fluid, while 

 others contained brown or red, gelatinous, fibrinous material. The tumor was 

 intimately associated with the underlying muscle. Both lungs were quite firm 

 and almost completely infiltrated with gray-\ ellow tissue. The tumor in the region 

 of the breast was composed of a mixture of fibroblastic and large macrophage-like 

 cells (Folate VII, Figure 2). Debris of engulfed cells was evident in the cytoplasm 

 of the large macrophages. In some areas the cytoplasm of the fibroblast-like 

 cells had become fused to form a relatively solid mass of tissue. The histologx' 

 of the tumor in the lungs was similar to that in the breast region. An incidental 

 finding in this case was a small benign hemangioma occurring as a small nodule 

 in the liver. 



Jutlging from experience with these cases, considerable study is required to 

 make a differential diagnosis between histiocytic sarcoma and fibrosarcoma; 

 yet essential difterences occur which indicate that these tumors ma>' be regarded 

 as separate and distinct forms of neoplasia. 



Neurogenic Sarcoma 



Five neoplasms aniong the collection of chicken tumors were classified as 



neurogenic sarcoma. One of these (Case 447) has been previously described 



(Olson 23) and the others are new to the literature. The salient features of the 

 five cases are as follows. 



1. Case 447. A pullet was killed for examination at the age of 23 weeks after 

 having shown symptoms resembling those of fowl parahsis for about a month. 

 A firm, encapsulated mass was found attached to the elements of the right brachial 

 nerve plexus. Some of the tumor was growing in the vertebral canal and com- 

 pressed the spinal cord. The greater mass of the tumor extended toward the base 

 of the heart and the thyroid gland, being connected with the part in the vertebral 



