Transplantable Lymphosarcoma of the Chicken

The tumor described in this paper arose in a Leghorn chicken selected for examination because of its pale comb and emaciation. Examination of the blood revealed a severe change of erythroblastic type with the presence of numerous pathological elements difficult of classification. In nuclear structure the cells resembled at times lymphoblasts and at other times, hemocytoblasts. Nucleoli were present and the cytoplasm was strongly basophilic. Many of the cells were in mitosis. No granulocytes were observed. At autopsy the liver was found to be enlarged, weighing ~3 o gin. It was covered with grayish white spots, measuring o.I to 2. 5 cm. in diameter, separated by hepatic tissue of normal color. On section the organ appeared to be transformed into a mass of grayish white nodules of various sizes. On microscopic examination the normal hepatic tissue was found to be reduced to narrow bands separating the neoplastic nodules. The latter consisted of a loose connective tissue stroma containing accumulations of large round tumor cells with a nucleus rich in chromatin and showing nucleoh. The cytoplasm of some cells was scanty and of others, abundant. In some cells the chromatin was less profuse and was distributed in the form of a network, while the cytoplasm stained less deeply. Mitosis was observed in cells of both types. The arteries of the liver were intact, but the veins frequently showed destruction of their walls, and neoplastic tissue was present in the lumen at some points. In some places the small periportal veins were obliterated by compression. Although there were few blood vessels in the neoplasm itself necrosis was not