Nonneoplastic Lesions of the Ovary

Imaging in gynecological disease (10): clinical and ultrasound characteristics of decidualized endometriomas surgically removed during pregnancy

“…Formation of ectopic decidua during pregnancy is attributed to hormonal effects on ectopic endometrium, i.e. endometriosis 3 , or on normal subcelomic mesothelium 4,5 . It has been hypothesized that decidualization represents a physiological reaction of the peritoneal stromal cells to pregnancy 5 .…”

“…endometriosis 3 , or on normal subcelomic mesothelium 4,5 . It has been hypothesized that decidualization represents a physiological reaction of the peritoneal stromal cells to pregnancy 5 . However, to the best of our knowledge, the prevalence of decidualized endometriomas has not been reported.…”

“…Ectopic decidual peritoneal foci may sometimes be visible on macroscopic examination as variably sized, soft, tan to hemorrhagic nodules or patches 5 . They are usually only seen microscopically 5 , but sometimes they may result in large peritoneal nodules mimicking malignancy and even obstructing labor 6 .…”

“…Smooth muscle cells may be admixed. Distended capillaries and numerous lymphocytes are typically found within the decidual foci 5 .…”