Discrepancy between ultrasonography and hysteroscopy and histology of endometrium in postmenopausal breast cancer patients using tamoxifen

Background. The increased risk of endometrial carcinoma following the use o f tamoxifen has stimulated studies on endometrial diagnostic screening meth ods. In tamoxifen users the endometrial thickening observed with transvagin al ultrasonography (TVU) frequently cannot be confirmed by hysteroscopy or histology. Objective. The aim was to investigate the relationship between TW and hyste roscopic and histologic endometrial findings in postmenopausal patients usi ng tamoxifen. Methods. Fifty-three asymptomatic postmenopausal tamoxifen-using breast can cer patients underwent a gynecological examination combined with TVU, Patie nts with an endometrial thickness of >5 mm were offered hysteroscopy and en dometrial biopsy. Findings. Thirty-one patients (58%) had an endometrial thickness of >5 mm w ith enhanced, inhomogeneous echogenicity. Hysteroscopy was performed in 22 patients and 3 underwent hysterectomy. Seven of 22 patients had endometrial polyps, histologically characterized by cystically dilated glands lined wi th atrophic epithelium and periglandular stromal condensation. Histology of the three hysterectomy specimens showed a similar picture of atrophic lumi nal epithelium, covering dilated glands lined with atrophic epithelium and surrounded by dense stroma, which resembled the histology of the endometria l polyps. In all three specimens the histologically measured endometrial th ickness corresponded with that on TW. Interpretation, Tamoxifen can induce specific endometrial changes consistin g of cystically dilated glands with periglandular stromal condensation whil e the overlying epithelium remains atrophic. The changes occur either in th e endometrium itself or as a protrusion of the endometrium, i.e., as endome trial polyps. These findings explain the discrepancy between ultrasound, hy steroscopy, and histology. Due to the high number of false-positive finding s, TVU is not an effective screening instrument in these patients, (C) 1999 Academic Press.