The Molecular and Cellular Mechanisms of Endometriosis: From Basic Pathophysiology to Clinical Implications

Endometriosis is a complex gynecological disorder characterized by endometrial-like tissue growing outside the uterus, leading to chronic pain, infertility, and reduced quality of life. Its pathophysiology involves genetic, epigenetic, immune, and molecular factors. Theories such as retrograde menstruation, coelomic metaplasia, and stem cell involvement explain lesion formation. Endometrial mesenchymal stem cells (eMSCs) and epithelial progenitors (eEPs) contribute to lesion establishment by adhering to peritoneal surfaces, proliferating, and differentiating into ectopic tissue. Aberrant adhesion molecules, inflammatory cytokines, and molecular pathways like PI3K/Akt and Wnt/β-catenin drive proliferation, angiogenesis, and resistance to apoptosis. Elevated estrogen levels and progesterone resistance further promote lesion growth and immune evasion. Immune dysfunction, including altered macrophage activity and reduced natural killer (NK) cell function, contributes to inflammation and lesion persistence. Pain is linked to prostaglandin E2 (PGE2) and nerve infiltration, emphasizing the need for targeted pain management. Current therapies, such as GnRH agonists, suppress ovarian hormone production but face limitations in long-term efficacy and side effects. Integrating molecular insights into clinical practice may advance diagnostics and treatment, with emerging approaches focusing on molecular pathways, immune modulation, and hormonal regulation for more effective, personalized therapies. Future research should unravel the complex mechanisms driving endometriosis to improve patient outcomes.