Endometriosis

Abstract

Endometriosis, defined as the presence of endometrial glands and stroma outside the endometrium, is a common gynecological disorder affecting women in reproductive age, associated with chronic pelvic pain and infertility. Its pathogenesis is complex and still unclear, probably multifactorial. The ovaries are the most common sites affected, but endometriosis can involve the gastrointestinal tract, urinary system, thorax, and soft tissue. We consider the anatomic subdivision of pelvic endometriosis into three forms: the adenomyosis, the tubo-ovarian lesions, and the deep pelvic endometriosis (DPE), defined by the invasion of endometrial tissue at least 5 mm beneath the peritoneal surface. The diagnosis and the accurate evaluation of the endometriosis extension are very important to avoid mutilating surgery and enhance fertility, but are often difficult only with physical examination and laparoscopy. The laparoscopy with histological confirmation remains the reference standard for diagnosis and staging, but it has limitations in detecting deep locations hidden by adhesions or located in the subperitoneal space. Ultrasound (transabdominal or transvaginal) is usually the first-line imaging modality in women with pelvic pain, but it has poor accuracy for deep pelvic endometriosic lesions. We would highlight the role of magnetic resonance (MR) imaging in the diagnosis of endometriosis that has already emerged as a high reproducible method to explore ovarian endometriosis; it demonstrates high accuracy also in the evaluation of DPE, allowing a complete survey of the anterior and posterior compartments of the pelvis, with high spatial resolution and good tissue characterization.