Morphological and biological characteristics of X-ray induced transplantable ovarian tumors.

The observation that total body irradiation in female mice is frequently if not inevitably followed by the development of ovarian tumor (8) has been confirmed and extended by several investigators (13, 15, 17, 19). The induction period of the tumors is very long. While regenerative changes begin after 4 to 6 months (5), tumor-like growth does not appear before about 7 months ; large tumors are in frequent and metastases are rare. Six years ago experiments were begun to ascer thin by transplantation studies the neoplastic character of the hyperplastic nodules that occur following irradiation and to secure pure lines of neoplastic cells of different sorts. Transplantations are suitable to study the morphogenic potencies of the ovarian tumor cells of different types, their interrelationship and the secondary changes they produce. Thus, 16 ovarian tumor strains have been studied, of which a luteoma has already been de scribed in extenso (9). The successful transplanta tion of granulosa tumors and their striking second ary changes have been recorded in preliminary reports (6). It is the purpose of this paper to survey the characteristics of the 16 strains of transplantable ovarian tumors and to find outwhat they contribute toward the understanding of ovarian tumor prob lems. Fifteen attempts to transplant x-ray induced tumors were unsuccessful in the first passage. Most of these were done under unfavorable conditions * This work formerly received support from the National Advisory Cancer Council. @ Published with the permission of the Chief Medical Director, Department of Medicine and Surgery, Veterans Ad ministration, who assumes no responsibility for the opinions cx pressed or the conclusions drawn by the author. and in a small number of mice, and will not be re viewed. Tumors arising in irradiated ovaries are corn plex. Most transplanted neoplasms are of the granulosa cell type ; a smaller number are luteomas and tubular adenomas. All of these types are fre quently present in the same x-rayed ovary, and the type of tumor particles used for transplantation, the growth rate of the different elements, and probably other factors residing in host tissue and donor determine which and how many types of transplantable neoplasms are isolated from a single irradiated ovary. Less commonly encountered neo plasms are hemangiomas and endotheliomas, (two of which resembled chorio-epitheliomas) and save omas. Only two types of cells thus far trans planted were found to be associated with hormone production: granulosa cell …