Concordance between hysteroscopic impression and endometrial histopathological diagnosis

The aim of this study was to evaluate the accuracy of hysteroscopic impression for diagnosing benign and malignant endometrial pathology.

This is a retrospective cross-sectional study involving case records of 412 patients who underwent hysteroscopy with diagnostic dilatation and curettage (D&C) at the University of Malaya Medical Centre from January 2009 to August 2011, and cases with records of previous hysteroscopies (2007-2008). Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, likelihood ratios (LR) and post-test probabilities of hysteroscopy were calculated. D&C was set as the 'gold standard'.

Hysteroscopy and histology results were concordant in 366 (88.8%) subjects. Sensitivity, specificity, PPV and NPV were high exceeding 80%. Moderate sensitivity for endometrial hyperplasia (64.4%, 95% CI=49.8%-76.8%) with moderate PPV for malignancy (62.1%, 95% CI=44.0%-77.3%) due to misdiagnosing hyperplasia as malignant was observed. PPV for leiomyoma was reduced (83.3%, 95% CI=60.8%-94.2%) despite 100% sensitivity, due to D&C false negatives. High positive LR (>10) and low negative LR (<0.2) were observed generally except for endometrial hyperplasia (0.36). Hysteroscopy had moderate positive post-test probability for malignancy (0.62) but effective in ruling out malignancy (negative post-test probability=0.00).

Hysteroscopy is accurate for diagnosing focal and malignant endometrial pathology but only moderate for hyperplasia. Endometrial sampling is recommended for all cases especially when suspecting hyperplasia or malignancy.