Study objective: We sought to assess accuracy of visual diagnosis of laparoscopically excised visceral and peritoneal abnormalities suggestive of endometriosis by comparison with final histologic diagnosis.
Design: Prospective study of 2005 tissue specimens from 512 patients undergoing laparoscopy for evaluation of pelvic pain was conducted (Canadian Task Force classification II-2).
Setting: A private practice referral center for treatment of endometriosis.
Patients: From February 1992 through December 1998, 512 patients underwent laparoscopic excision of endometriosis. In all patients, the primary indication for surgery was pelvic pain with either prior surgical diagnosis or clinical history consistent with endometriosis.
Interventions: All areas of viscera and peritoneum either with typical appearance suggestive of endometriosis or atypical appearance were completely excised and examined histologically. At laparoscopy, all excised lesions were documented in a diagram by the primary surgeon according to anatomic site and visual description and were labeled as either suggestive of endometriosis or otherwise atypical in appearance. The hospital pathology department received entire lesions fixed in formalin and evaluated specimens for presence or absence of endometriosis. Pathologists, who were blinded to the surgeon's suspicion of endometriosis, were provided only the anatomic site of excised tissue. By definition, diagnosis of endometriosis was made when histologic evidence existed of both endometrial glands and stroma.
Measurements and main results: Diagrams detailing appearance, anatomic site, and surgeon's suspicion of endometriosis versus atypical lesions were compared with final histologic diagnosis. The greatest number of patient lesions were excised from cul-de-sac (n = 309). For this site, using visual criteria for diagnosis of endometriosis, positive predictive value was 93.9%, sensitivity was 69.3%, negative predictive value was 41.9%, and specificity was 83.1%. Prevalence was noted to be 79.0% and accuracy was 72.2%. In addition, atypical-appearing tissue not presumed to be endometriosis was confirmed to be endometriosis histologically in 24.3%. In examining tissue specimens from multiple anatomic sites, laparoscopic visual diagnosis of typical endometriosis generally had high positive predictive value. However, both sensitivity and negative predictive value were lower than expected because of atypical lesions subsequently diagnosed as endometriosis.
Conclusions: These data suggest that when the surgical objective is complete eradication of endometriosis, the surgeon must be prepared to excise all lesions suggestive of endometriosis and tissue atypical in appearance as in most anatomic sites approximately 25% of atypical specimens proved to be endometriosis.