Materials and Methods: In this retrospective cross-sectional study, medical records of 124 women diagnosed with endometrial hyperplasia who underwent subsequent hysterectomy between 2018 and 2023 at Kamali hospital, Karaj, were reviewed. Preoperative endometrial sampling was performed via Pipelle (n=65) or D&C (n=59). Histopathological results from both methods were compared with the final hysterectomy findings. Diagnostic accuracy, sensitivity, specificity, and concordance rates were calculated.

Results: The overall diagnostic concordance with hysterectomy findings was 72.88% for D&C and 70.76% for Pipelle. For the detection of atypia, D&C showed a sensitivity of 76% (95% CI: 52%–92%), specificity of 86% (95% CI: 72%–96%), and accuracy of 83% (95% CI: 71%–91%), while Pipelle demonstrated a sensitivity of 73% (95% CI: 54%–87%), specificity of 80% (95% CI: 63%–91%), and accuracy of 77% (95% CI: 65%–86%). The confidence intervals for these metrics overlapped substantially. No statistically significant differences were found between the two methods in direct comparisons (P>0.05). D&C was associated with a lower rate of pathological upgrading than Pipelle (13.16% vs. 22.22% for missed atypia). However, this difference was not statistically significant (P=0.31).

Conclusions: Both Pipelle and D&C demonstrate comparable diagnostic performance, with high and statistically similar concordance rates with final hysterectomy pathology. D&C shows a non-significant trend towards higher accuracy and a lower rate of missed atypia. Clinicians should be aware of the potential for underdiagnosis of atypia with both methods, particularly with Pipelle, when planning management strategies for endometrial hyperplasia.