Objective: To investigate the accuracy of endometrial sampling in
 the diagnosis of endometrial pathology and the need of intraoperative
 frozen section.
 
 Methods: One hundred forty women who underwent endometrial
 sampling followed by hysterectomy between 2011 and 2014 were
 included in this study. Data were retrieved from patient files and
 pathology archives in Department of Obstetrics and Gynecology,
 Jose R. Reyes Memorial Medical Center, Manila, Philippines.
 
 Results: There were 25 patients with malignancy but endometrial
 sampling detected only 22 of them. The endometrial sampling
 sensitivity and specificity for detecting cancer were 88% and 100%,
 respectively with negative and positive predictive values of 97.5%
 and 100%, respectively. In 3 patients, the endometrial sampling
 failed to detect malignancy; 1 patient had a preoperative diagnosis
 of complex hyperplasia with atypia, 1 patient had complex
 hyperplasia without atypia and 1 patient had adenofibroma. A total
 of eighty patients had benign findings. There were fifty-three cases
 with finding of proliferative endometrium and twenty-seven were
 secretory. Twenty-three (55.0%) and 11 (39.0%) cases were
 confirmed by the hysterectomy specimen, respectively. The
 sensitivity of endometrial sampling in detecting benign samples was
 76.0% and the specificity reached up to 83.0%. The histopathology
 result of the other fourteen cases were reported of having atrophy,
 twelve cases were reported of having endometrial hyperplasia, four
 with basal endometrium, four with endometrial polyp and one with
 adenomyosis.
 
 Conclusion: Outpatient endometrial biopsy has a high overall
 accuracy in diagnosing endometrial cancer when the specimen
 obtained is sufficient. A positive test result is more accurate for
 ruling in disease than a negative test result is for ruling it out.
 However, the diagnosis should be confirmed by frozen section in
 patients with complex hyperplasia and adenofibroma.
 
 [Indones J Obstet Gynecol 2017; 5-1: 23-29]
 
 Keywords: abnormal uterine bleeding, endometrial hyperplasia,
 endometrial sampling, frozen section, pipelle