P-344: Diagnosis of stage I endometriosis: Comparing visual inspection to histologic biopsy

Abstract

Endometriosis is frequently diagnosed by visual inspection however correlation of surgical impression with histology is variable, particularly in patients with stage I disease. Although pathology is the only way to definitively diagnose endometriosis, controversy exists as to whether biopsy is necessary to confirm the presence of disease. The objective of our study is to evaluate the positive predictive value (PPV) of surgical diagnosis compared to biopsy findings by severity of disease. Retrospective case series. Patients from an academic referral center who had laparoscopic biopsies for suspected endometriosis were included. In ten consecutive months 156 patients received diagnosis of endometriosis at laparoscopy. 104 of these patients had biopsies. The same surgeon performed all the surgeries. The location of the biopsies were recorded and sent to pathology for diagnosis. Revised ASRM endometriosis classification (1996) was used for staging. The pathologic diagnosis was then compared to the original stage of endometriosis at the time of surgery and the PPV was calculated. Chi-square analysis was done to evaluate biopsy accuracy by stage and location per biopsy and per patient. A total of 238 biopsies were taken from 104 patients. The ages of the patients ranged from 13-65 averaging 35.96 ± 7.58. The overall PPV was 87% for all patients. There were a total 73 suspected endometriomas removed and 165 peritoneal implants excised. The PPV per biopsy of stage I- IV endometriosis was 66%, 78%, 92% and 81% respectively (Table 1). The PPV per patient of stage I- IV endometriosis was 75%, 89%, 100%, and 90 % respectively (Table 2). Stages II-IV were significantly more likely to be confirmed by biopsy than stage I disease. When endometriomas and peritoneal biopsies were analyzed separately there was no difference in PPV (79% vs. 77%).Tabled 1Tabled 1 There was a high PPV for all patients in our study. However, when stage I endometriosis when compared to stages II-IV PPV was significantly lower. The PPV per patient was higher than the PPV per biopsy indicating that the ability to diagnose endometriosis may be improve by performing multiple biopsies. PPV of visual inspection is high, but not without errors. Therefore, in order to avoid misdiagnosis particularly in stage I disease, every attempt should be made to confirm diagnosis by biopsy.