CD10 immunohistochemical staining enhances the histological detection of endometriosis.

OBJECTIVE: To determine whether the use of CD10 immunohistochemistry in addition to hematoxylin and eosin (H&E) staining would increase the sensitivity of surgically suspected endometriosis lesions.
DESIGN: Retrospective cohort study.
SETTING: Tertiary care government research hospital. PATIENT(S): Thirty-one women with chronic pelvic pain. INTERVENTION(S): Immunohistochemical analysis for CD10 was performed on 108 possible endometriotic lesions and in the corresponding endometrial biopsy samples obtained during laparoscopy. When CD10 immunohistochemistry results were positive, the corresponding H&E section was reviewed to determine if the initial diagnosis should be revised. MAIN OUTCOME MEASURE(S): Histologic diagnosis of endometriosis by adjunctive use of CD10 immunohistochemistry in conjunction with H&E-stained specimens. RESULT(S): In endometrial stroma, CD10 was consistently present. Of the 70 specimens judged negative initially by H&E staining, CD10 staining led to the diagnosis of endometriosis in 11. The addition of CD10 immunohistochemistry detected more positive endometriosis lesions than H&E staining alone (45% vs. 35%). In three women with minimal endometriosis at surgery but initially negative histopathology, CD10 immunohistochemistry changed the histologic diagnosis to endometriosis. CONCLUSION(S): The adjunctive use of CD10 immunohistochemistry improves diagnostic sensitivity for endometriosis, especially for women with minimal disease.