The effect of tamoxifen on the genital tract

Abstract

Tamoxifen is a selective estrogen receptor modulator (SERM) that is widely used in the treatment of patients with breast cancer and for chemoprophylaxis in high risk women. Tamoxifen results in a spectrum of abnormalities involving the genital tract, the most significant being an increased incidence of endometrial cancer and uterine sarcoma. This article reviews the effects of tamoxifen on the genital tract and the strengths and weaknesses of various imaging modalities for evaluating the endometrium.

Figure 1

(a,b,c) Sagittal transvaginal ultrasound images from three different patients show the most common endometrial finding in women undergoing tamoxifen treatment: a thickened endometrium with cystic spaces. Calipers in (a) and (c) denote the endometrial thickness. (b) Reprinted with permission from Ascher et al.^[16].

Figure 2

Hysterosonography as an adjunct to transvaginal ultrasound. (a) Sagittal transvaginal ultrasound in a women treated with tamoxifen demonstrates a retroverted uterus with a thickened endometrium. Calipers denote the endometrium. (b) Sagittal hysterosonogram showed no evidence of endometrial mass or thickening. The apparent thickening on the transvaginal ultrasound was secondary to subendometrial/myometrial cysts.

Figure 3

Hysterosonography as an adjunct to transvaginal ultrasound. (a) Sagittal transvaginal ultrasound demonstrates markedly thickened endometrium. (b) Sagittal hysterosonogram shows three broad based polyps. These were found to represent malignant endometrial polyps.

Figure 4

Hysterosonography as an adjunct to transvaginal ultrasound. Sagittal transvaginal ultrasound demonstrates a markedly thickened, heterogeneous endometrium. Calipers denote the endometrium. (b) Transverse view from hysterosonogram demonstrates irregular thickening with of the endometrium with internal vascularity which was found to represent endometrial carcinoma.

Figure 5

Pattern 1 MRI findings of the uterus in breast cancer patients treated with tamoxifen. (a) Transverse transvaginal ultrasound image shows small cysts around the endometrial complex. (b) Sagittal T2-weighted fast spin-echo MR image demonstrates a retroverted uterus with a normal thin homogenously high signal intensity endometrium and cysts at the endometrial–myometrial junction. (c) Sagittal transvaginal ultrasound shows a retroverted uterus with a thickened endometrial complex measuring 6 mm (calipers) with small cystic spaces. Sagittal gadolinium-enhanced spoiled gradient-echo MR image shows the endometrial lumen is a signal void. Enhancement of the endometrial–myometrial interface with endometrial–myometrial cysts. (a,b) Reprinted with permission from Ascher et al.^[16]. (c,d) Reprinted with permission from Ascher et al.^[90]

Figure 6

Pattern 2 MRI findings of the uterus in a breast cancer patient treated with tamoxifen. (a) Sagittal T2-weighted fast spin-echo MR shows a thickened endometrium with heterogeneous signal intensity. (b) The corresponding sagittal gadolinium-enhanced spoiled gradient-echo MR image shows lattice-like enhancement traversing the endometrial canal and was found to represent a benign endometrial polyp. (The corresponding ultrasound is shown in Fig. 1b.) Reprinted with permission from Silva et al.^[91].

Figure 7

A 71-year-old woman with breast cancer treated with tamoxifen. (a) Sagittal T2-weighted fast spin-echo image of the uterus shows a widened endometrial canal with heterogeneous signal intensity. (b) Contrast enhanced sagittal-T1-weighted fat-suppressed spoiled gradient-echo image shows enhancing tissue traversing the endometrial canal. An enhancing stalk originating from the posterior endometrium allows the diagnosis of polyp to be established with confidence. Reprinted with permission from Ascher et al.^[90].