Endometrial abnormalities associated with tamoxifen therapy for breast cancer: sonographic and pathologic correlation

Tamoxifen is widely used to treat breast carcinoma in postmenopausal women. Previous studies have suggested an increased prevalence of endometrial carcinoma and polyps after treatment with tamoxifen. We correlated findings on pelvic sonograms with pathologic findings in a group of patients treated with tamoxifen.

We reviewed the pelvic sonograms and medical histories of 14 postmenopausal women with breast carcinoma who were being treated with tamoxifen. Pathologic correlation was available in the 11 cases in which adequate tissue was obtained. Coexisting pathologic changes were found in seven patients. Pathologic examination showed a total of 18 endometrial abnormalities, including nine cases of uterine polyps, four cases of hyperplasia, two cases of endometritis, one proliferative endometrium, one inactive endometrium, and one case of carcinoma.

Sagittal sonograms of all 11 patients with pathologic correlation showed abnormal endometrial thickening measuring more than 7 mm. The sonographic appearance of the endometrium in these patients included hyperechoic, homogeneous tissue; hyperechoic tissue with multiple, small cystic spaces; heterogeneous tissue with small cystic spaces; and solid tissue that was heterogeneous. Small cystic spaces were seen in all cases of polyps. Six of the nine cases of polyps were associated with other endometrial abnormalities also. The single case of endometrial carcinoma appeared solid and heterogeneous on sonography; however, further pathologic examination of the surgical specimen showed a coexisting polyp.

Tamoxifen therapy is associated with several findings on sonograms of the uterus. Because several pathologic findings frequently coexist, sonography is of limited use in the diagnosis of specific abnormalities.