Endometrioma

Endometrioma is a specific cystic formation of the ovary that manifests as external genital endometriosis (primarily stages III-IV), whose cavity is filled with dense hemorrhagic content.

Etiology and pathophysiology

Current theory of pathogenesis suggests invagination of superficial cortical foci of endometriosis into the ovarian tissue. The epithelial lining of the cyst wall is histologically similar to the uterine mucosa: it comprises hormone receptors and menstruates into the enclosed cavity. The accumulating blood has no outlet, undergoes hemolysis and thickening. Hemoglobin transforms into hemosiderin, giving the contents a characteristic ‘liquid chocolate’ or tar-like appearance.

Clinical significance

Endometriomas exert a pronounced negative impact on reproductive potential: they mechanically compress healthy ovarian tissue, causing ischemia and fibrosis, and the toxic contents of the cyst (free iron, cytokines) damage oocytes in neighboring follicles, reducing the ovarian reserve and Anti-Müllerian Hormone (AMH) levels. Rupture of the cyst leads to chemical peritonitis and severe pain.

The gold standard treatment is laparoscopic cystectomy (capsule shelling), which must be conducted precisely to preserve the follicular apparatus.