[The mechanism of the increase in the serum CA125 concentration in patients with endometriosis].

We discussed the mechanism of the increase in CA125 among patients with benign gynecologic diseases, especially with endometriosis. The tissue CA125 concentrations of surface endometrium in patients with adenomyosis were as follows; the highest tissue concentration was observed at the early proliferative phase followed by the late secretory one and was lowest in the late proliferative one. The tissue CA125 concentration showed the significantly different characteristics in surface and ectopic endometrium. The increase in CA125 in the intraperitoneal fluids was observed among cases of early pregnancy, acute appendicitis and ovarian hyperstimulation syndrome (OHSS). Tissue samples from both the peritoneum obtained from patients with acute appendicitis and the cyst wall obtained from OHSS cases showed a high concentration of tissue CA125. From these findings, it was suggested that one of the causes of serum CA125 increase in patients with adenomyosis appeared to be the increase in the ectopic endometrial tissues in the myometrium and direct shedding from ectopic endometrial cells into peripheral circulation. On the other hand, in patients with chocolate cysts, the increase in serum CA125 was suppressed because it was secreted into the inside of the chocolate cyst. The production of CA125 may take place not only from ectopic endometrial cells of adenomyosis but also from the peritoneal tissues of patients with acute appendicitis.