Localization of mast cells in endometrial cysts.

PROBLEM: Although the presence of mast cells in endometriosis lesions has been reported, there have been no reports of their pathological localization in ovarian endometrial cysts. METHODS OF STUDY: The localization of mast cells in ovarian endometrial cysts were investigated using hematoxyline and eosin and toluidine blue staining with light microscopy, immunohistochemical c-kits, and electron microscopy. RESULTS: Mast cells were identified in endometrial cyst tissues. Few mast cells were localized in the endometrial stroma, which is characteristic of endometrial gland-like regions. Many mast cells were noted around blood vessels and the interstitium with fibrosis, that is, the fibrotic interstitium of endometrial cysts. CONCLUSIONS: Mast cells may be involved in the development and progression of endometriosis. Localization of mast cells suggests a particularly close relationship with fibrosis and adhesion.