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 mm(2) +/- 55.9 ( range, 1.6-125) and for curettings was 21.6 per mm(2) +/- 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.