Endometrioma

An endometrioma is a type of cyst that forms when a cluster of normal hormonally sensitive endometrial tissue grows outside the uterus. It is a benign growth and the most commonly detected form of endometriosis. Typically an endometrioma is located on or near the ovaries. Normal endometrial tissue during the menstrual cycle, thickens, breaks down, then bleeds, with these products exiting the body. However when this cluster of endometrial tissue is located outside the uterus it has no way to exit the body and forms an endometrioma. If an endometrioma grows larger than 9cm in diameter, (approximately 1% of all endometriomas) there is a possibility for the endometrioma to turn malignant.Endometriomas that are smaller than 5mm are considered early stage disease, and may be too small to be seen other than at surgery. Endometriomas that are larger than 15mm are considered advanced stage disease.