The transformation of a solid transplantable mouse carcinoma into an "ascites tumor".

Because the Ehrlich ascites tumor possesses certain advantages for some quantitative studies on the growth rate and the chemical components of tumor cells (3), the mechanism of the transformation of another solid transplantable mouse carcinoma into an ascites tumor was investigated. After the intraperitoneal inoculation of solid tumor masses, a peritoneal carcinomatosis developed. The peritoneal exudates produced were used for subsequent intraperitoneal injections through several transplant generations. A gradual increase in the relative frequency of tumor cells in the fluid could be observed, and, finally, the nearly “pure culture” state of tumor cells could be reached—which corresponds to the definition of “ascites tumor.” Several characteristics of this newly produced ascites tumor are compared to the classical Ehrlich ascites tumor. The relationship between solid growth in the peritoneal cavity and growth of the cell suspension in the ascitic fluid are shown to be dependent upon the initial number of cells inoculated. The mechanism of the transformation into an ascites tumor is discussed.