CARCINOGENESIS BY IONIZING RADIATIONS 



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tumors arising in irradiated ovaries are complex (Bali and Furth, 1949). 

 Most transplantable neoplasms are of the granulosa cell type; a small 

 number are luteomas and tubular adenomas. All these types are fre- 

 quently present in the same irradiated ovary. Less commonly encoun- 

 tered neoplasms were hemangiomas and endotheliomas (two of which 

 resembled chorioepitheliomas) and sarcomas. Only two types of cells 

 thus far transplanted were found to be associated with hormone produc- 

 tion: granulosa cell tumors causing morphological changes indicative of 

 the production of estrogens, and luteomas with changes indicative of 

 progestin production. It is not known whether all small tumorlike 

 nodules in the ovary of X-irradiated mice are autonomous growths, but 



Fig. 18-8. Unilateral ovarian tumor (lacteoma) in a mouse induced by total-body 

 exposure to X rays with hormonal hyperplasia of the uterine horns (after Furth and 

 Butterworth, 1936). 



five types have been grafted on normal hosts : granulosa tumors, luteomas, 

 tubular adenomas, sarcomas, and angioendotheliomas. The granulosa 

 tumors occur in a wide range of morphological forms similar to those seen 

 in woman and simulate so many different types of neoplasms that their 

 identification on a morphological basis alone is often not possible. Their 

 common denominator is the ability to produce or initiate production of 

 estrogens and plethorins (a hypothetical substance that raises blood 

 volume— Sobel and Furth, 1948) although not all tumor-bearing hosts 

 show the effects of these substances. 



Investigators who have attempted to describe the morphogenesis of 

 ovarian neoplasms have arrived at contradictory conclusions (Bali and 

 Furth, 1949). Some trace their origin to the covering germinal epi- 

 thelium, some to stromal cells (ovariocytes). The chief pacemakers of 

 the ovarian cycle are the pituitary gland and the ova. The latter gradu- 



