A pilot study to evaluate the relative efficacy of endometrial biopsy and full curettage in making a diagnosis of endometriosis by the detection of endometrial nerve fibers

Objective: The purpose of this study was to evaluate endometrial biopsy and curettage in detecting small nerve fibers in eutopic endometrium for diagnosis of endometriosis. Study Design: Endometrial biopsies with precise, consistent technique and curettings were taken from 37 women (20 with endometriosis and 17 without endometriosis). Sensitivity, specificity, and positive and negative predictive value were formally calculated. Endometrial nerve fibers were immunohistochemically detected using the pan-neuronal marker PGP9.5. Results: Small nerve fibers were detected in all endometrial biopsies and curettings from all 20 women with endometriosis, but were not detected in endometrium taken from 17 women without endometriosis. Mean (±SD) nerve fiber density in the endometrial biopsies was 26.8 per mm² ± 55.9 (range, 1.6-125) and for curettings was 21.6 per mm² ± 33.1 (range, 0.8-250), with 100% specificity, sensitivity, and positive and negative predictive value. Conclusion: Careful endometrial biopsy combined with immunohistochemical staining for nerve fibers may be a reliable means of diagnosing or excluding endometriosis.