[GANN, Vol.42; March, 1951] CYTOLOGICAL AND LEUKEMIO-PATHOLOGICAL PROBLEMS CONCERNING THE YOSHIDA SARCOMA (A MONOCYTIC TUMOR OF THE RAT) (With Plates I and II)

Yoshida reported a new transplantable tumor of the rat under the title of "the new strain of transplantable ascites sarcoma" (Yoshida, Muta . Sasaki, 1944). According to his own abstract: "This tumor shows the morphological picture corresponding to reticulosareoma, and, cytologically, the cell is several times as large as the leucocytes; its indented nucleus leans to one side, and a neutral-red rosette exists near the indentation of the nucleus; the oxidase reaction is weakly positive, and as to the size and the form of the nucleus it varies to a great extent, but it is interesting to compare this cell with the lymphocyte or monocyte." After the examination of the smears, Amano, our leader and cooperator, insisted that this tumor should be classified equally with the monocytic tumor, i.e., green monocytoma (so-called chloroma) or not-green monocytoma (in further anaplastic state in which the cell ceases to produce the green pigment), based on the similarity of the character of this tumor cell to that of the monocyt. (Amano: Fundamental Problems of Hematology, 1948). As to the cytological character of this tumor cell, Yoshida once referred it to the histiocyte, while afterwards he thought that it belongs probably to the monocyte, which opinion was generally accepted (Yoshida, 1947, Special-report in the Jap. Path. Soc.). Hamazaki, however, from a new view-point, asserted that this tumor should be regarded as the coelothelioma of the abdominal cavity (1948, Discussion at the Jap. Cancer Association; 1949, and his report "a cytological study on Yoshidasarcuma," Acta Hemat. Jap.). If this tumor is the coelothelioma of the abdominal cavity, how can we understand the following properties of this tumor cell, namely to be free in the abdominal cavity, and consequently, the possibility to