Can we rely on blind endometrial biopsy for detection of focal intrauterine pathology?

To compare the diagnostic power of random endometrial biopsy with hysteroscopy for intrauterine lesions.

A retrospective cohort study of 639 women evaluated by diagnostic office hysteroscopy and endometrial biopsy (Novak curette) was carried out between 10/1997-6/2000. Reasons for evaluation were postmenopausal bleeding, abnormal uterine bleeding, ultrasound or hystero-salpingography findings, intrauterine device removal, suspected retained products of conception, infertility, late abortions and recurrent abortions.

The women's mean age was 43.4+/-13.3 years (range, 18-88). The most prevalent indication for investigation was abnormal uterine bleeding (n=218, 34.1%), followed by sonographic or hystero-salpingographic findings (n=167, 26.1%). Hysteroscopy revealed a normal uterine cavity in 367 (57.4%) women. Endometrial polyps and submucosal fibroids were the most common hysteroscopic findings (in 151 [23.6%] and 72 [11.3%], respectively). The hysteroscopic findings were compared with the pathology results in 558 cases. The sensitivity of the Novak curette for detection of endometrial polyps and submucosal fibroids was only 8.4% and 1.4%, respectively. The positive predictive value (30.9%) and the negative predictive value (57.9%) for both lesions were likewise low. On the other hand, hysteroscopy was not effective in diagnosing the 27 cases of hyperplasia (26 simple and one complex) all without atypia.

Random endometrial sampling alone is not effective for diagnosing focal lesions of the uterine cavity and should be combined with other modalities, preferably diagnostic hysteroscopy.