Endometriosis in Four Irradiated Rhesus Monkeys

Four Rliesus monkeys that had been irradiated at 1 year of age and developed extensive endometriosis of the pelvic and peritoneal cavities 7 years later. Endometriosis was characterized by aggressive viable nonanaplastic endometrial epithelial cells in ectopic sites throughout the genital organs. Theories of pathogenesis for man may not be valid for nonhuman primates. Retrograde flow of endometrial fragments via the oviducfs may be the source of the extrauterine lesions since in monkeys I, 2, and 4 the ovaries were in the main extrauterine masses. Whether the extrauterine endo- metrium is metaplastic or metastatic, there is little doubt that endometriosis is linked to the cyclic hormones of the female's reproductive cycle. The cases reported occurred at 8 years of age, and the deaths may illustrate shortening or life as a latent effect of irradiation.