Classification of ovarian endometriotic cysts

Current literature describes 3 different pathogenetic types of ovarian endo metriotic cysts. Cortical invagination cysts arise when surface ovarian end ometriotic deposits adhere to another structure (such as the broad ligament ), blocking the egress of menstrual fluid produced by cycling endometriosis , which then collects and causes the ovarian cortex to invaginate. Surface inclusion cyst-related endometriotic cysts develop when endometriotic tissu e colonizes preexisting inclusion cysts. Physiological cyst-related endomet riotic cysts occur when endometriosis gains access to a follicle, such as a t the time of ovulation. To determine whether routine histological examinat ion is of use in the classification of endometriotic cysts, and if so, whet her such classification is of clinical relevance, we reviewed the histology of endometriotic cysts of 29 women under 35 years of age. Young women were chosen so that ovarian cortex surrounding the endometriotic lining in inva gination cysts could be identified by the finding of oocytes. Ten women (34 %) had cortical invagination endometriotic cysts, but no inclusion or physi ological cyst-related endometriomas were found. The remaining 19 women (66% ) had unclassified endometriotic cysts, of which 14 (48% of total) had a fi brous wall between the endometriotic lining and medulla and 5 had extensive destruction of ovarian tissue. We concluded that cortical invagination cys ts were the only common diagnosable sort of the 3 types currently being inv estigated and that unclassified cysts required further study to determine t heir pathogenesis. Our study highlights the need for a prospective study us ing standardized pathological and clinical methods.