The Negative Predictive Value of "Inadequate" Endometrial Biopsy in Diagnosing Endometrial Neoplasia

Objective: To evaluate the negative predictive value of endometrial samples that were reported as inadequate in diagnosing endometrial hyperplasia or malignancy. Study Design: The negative predictive value of an inadequate office endometrial sample for endometrial neoplasia was determined. Results: Seventy-eight cases were included in the study. Two patients were lost to follow-up. Thirty-seven (48.7%) of 76 women who had complete records had follow-up tissue diagnoses. The negative predictive value of inadequate endometrial biopsy sample in this group was 97.2%. The remaining 39 (51.3%) were followed by clinical examination and/or imaging studies only. When all 76 patients are considered, the negative predictive value of the inadequate endometrial biopsy sample increased to 98.7%. Conclusion: Our findings suggest that an inadequate office endometrial sample may be sufficient to rule out endometrial neoplasia because of its high negative predictive value.