Endometriosis: Diagnosis and Pathophysiology

Endometriosis is a chronic inflammatory hormone-dependent condition that is characterized by the presence of functional endometrial glands and stroma outside the uterus. It affects 6%–10% of women of reproductive age and is associated with pelvic pain symptoms and infertility. The pathophysiology of endometriosis is complex and multifactorial and includes theories such as retrograde menstruation, metaplasia, immune factors, precursor cell theory, genetic factors, and environmental factors. Although retrograde menstruation is one of the main theories, only 10%–15% of women with retrograde menstruation develop endometriosis, indicating that additional factors are involved. Genetic predisposition, environmental factors such as diet and lifestyle, and impaired immune function may contribute to the development of endometriosis. Endometriotic lesions may contain glands and blood and are frequently surrounded by fibrotic tissue. Endometriosis can be classified into different phenotypes, including peritoneal, ovarian, and deep infiltrating endometriosis. The presence of endometrial glands and stroma is the main characteristic of endometriosis on microscopic examination. Proper identification of lesions using imaging examinations is crucial for diagnosis and is the gold standard for proper surgical planning.