Iron overload in the peritoneal cavity of women with pelvic endometriosis

Objective: To examine the possible involvement of iron in the physiopathology of endometriosis. Design: Prospective study. Setting: Department of gynecology in a university hospital. Patient(s): Seventy patients undergoing laparoscopy. Intervention(s): Collection of peritoneal fluid (n = 57), blood samples, and biopsy samples from endometrium (n = 62) and from endometriotic (n = 33) and normal-appearing peritoneum (n = 53). Main Outcome Measure(s): Measurement of iron and ferritin in serum and peritoneal fluid and staining of iron deposits with Prussian blue in tissues. Result(s): Iron and ferritin concentrations were significantly higher in the peritoneal fluid of patients with endometriosis compared with controls during the secretory phase. Higher rates of ferritin and hemosiderin deposits were observed in the peritoneum adjacent to red (100%), black (57%), and white (62%) lesions compared with normal-appearing peritoneum (25%). Deposits were more frequent during the secretory phase than the proliferative phase in healthy peritoneum from controls, whereas they were found throughout the cycle in the vicinity of lesions in patients with endometriosis. Similar rates of iron deposition were observed in the stroma of black and white lesions and in eutopic endometrium from patients with endometriosis. Conclusion(s): Iron overload was observed in the cellular and peritoneal fluid compartment,, of the peritoneal cavity of women with endometriosis. Iron deposits seem to be related to the presence of lesions, suggesting that iron may be involved in the pathogenesis of endometriosis.