The Usefulness of CD34, PCNA Immunoreactivity, and Histopathological Findings for Prediction of Pain Persistence After the Removal of Endometrioma

Endometriosis is an estrogen-dependent inflammatory disease that causes infertility and chronic pelvic pain. Ovarian endometrioma is the most common form of endometriosis, and conservative surgery is the main preferred therapeutic approach for endometrioma-associated symptoms. The aim of this study was to investigate the persistence of cyclic and noncyclic pelvic pain (NCPP) after endometrioma excision and their relationship to clinical and histopathological findings. In this prospective observational study, 41 symptomatic patients were evaluated for the presence of pain symptoms 3 to 6 months after endometrioma excision. Tissue specimens of endometrioma were collected during the operation and embedded in paraffin. The persistence of pain was 41.4%. Surgical excision of endometrioma significantly decreased NCPP and dysmenorrhea, but not dyspareunia ( P <.0001, P =.0001, and P =.25, respectively). Histopathological changes, including depth of endometriosis penetration into the cyst wall, the presence of macrophage infiltration, and vascularity of endometrioma cyst walls were significantly higher in patients with pain persistence than in patients without pain persistence ( P =.0034, P =.0042, and P =.0007, respectively). Moreover, proliferating cell nuclear antigen (PCNA) and CD34 immunoreactivity in both glandular and stromal cells and vascular endothelium were significantly higher in patients with pain persistence ( P =.0079 and P =.0025, respectively). Additionally, these histopathological changes and PCNA and CD34 immunoreactivity were significantly correlated with the persistence of NCPP and dysmenorrhea. The discovered differences in patients with endometrioma with or without pain persistence may indicate a possible relationship between endometrioma-associated pain and histopathological variability of endometrioma.