Peritoneal lavage cytology in the diagnosis of pelvic endometriosis.

Background: We aimed to assess the sensibility, specificity, and predictive values of cytology of the fluid sediment in patients with pelvic endometriosis diagnosed based on laparoscopic-guided biopsy.

Methods: Between January 2017 and September 2018, 71 specimens of peritoneal fluid collected by laparoscopy were evaluated. Fifty-three patients were diagnosed laparoscopically and histologically with endometriosis, and 18 were considered controls (without suspicious endometriosis lesions). We calculated the sensitivity, specificity, the positive and negative predictive value, and the accuracy of endometrial-like cells (ELC) and hemosiderin-laden macrophages (HLM) in the fluid sediment.

Results: Of the 50 patients with endometriosis, 32 (64%) had HLM, 9 (18%) had ELC, and 7 (14%) had both elements. Of the 18 patients without endometriosis, 3 (16%) had HLM, 2 (11%) had ELC, and 1 (5%) had both ELC and HLM. The sensitivity of the cytology of peritoneal fluid sediment for the diagnosis of endometriosis, based on the presence of ELC, was 18%, the specificity was 83%, the positive predictive value was 82%, the negative predictive value was 28.7%, and the accuracy was 36.8%. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy based on the presence of HLM were 64%, 83%, 91%, 45.5%, and 69.1%, respectively.

Conclusion: The study of peritoneal fluids obtained laparoscopically from women undergoing evaluation for endometriosis may identify patients with the disease.