Disaccordance between estimation of endometrial thickness as measured by transvaginal ultrasound compared with hysteroscopy and directed biopsy in breast cancer patients treated with tamoxifen.

OBJECTIVE: To estimate endometrial thickness by transvaginal ultrasound technique (TVU) in patients treated with tamoxifen; and to compare the results with hysteroscopy and directed biopsy, and to relate the findings to curettage material. METHODS: Fifty-four women, over 50 years of age at the time of their primary breast cancer operation and scheduled for adjuvant treatment of tamoxifen, were investigated. If the endometrium measured 8 mm or more (35 patients) hysteroscopy and directed biopsy was performed. RESULTS: In the 35 patients, hysteroscopy and curretage revealed polyps in 18 cases (51.4%), proliferation in 1 case (2.9%) and atrophy in 16 cases (45.7%). In 54.3% (19 cases) of the patients the histopathological finding was a polyp or benign proliferation of the endometrium in agreement with the thickened endometrium seen with TVU. In the remaining 45.7% (16 cases) of the patients a thickened endometrium by transvaginal ultrasound was false positive as the hysteroscopic and subsequent histopathological diagnosis only showed atrofia of the uterine endometrium. CONCLUSIONS: In almost half of the patients the TVU gave a misleading picture concerning the condition of the endometrium. Changes in the myometrium and related connective tissue could be misinterpreted by the ultrasound technique as changes in the endometrium. These results may confirm the theory that stimulation and changes by antiestrogenic treatment of the uterine tissue is not only restricted to the endometrium. In patients with thickened endometrium measured by TVU, a dilatation and curettage is not sufficient, as TVU has not the ability to differentiate between endometrial polyps and myometrial changes. A hysteroscopy and directed biopsy could therefore be performed.