Sonographic characteristics of adenofibroma of the endometrium following tamoxifen therapy for breast cancer: two case reports

Abstract

Adenofibroma of the endometrium is thought to be a rare benign variant of the mixed mesodermal tumor, and its preoperative diagnosis is difficult. We describe the sonographic characteristics of two cases of adenofibroma of the endometrium. In both cases the patient was receiving prolonged tamoxifen therapy following surgery for breast cancer. Sonographically, this rare disease is observed as an intracavitary mass containing multiple small cysts with low-resistance intratumor blood flow. The unique sonographic findings make the preoperative diagnosis possible.

Benign endometrial adenofibroma and polyp in patients receiving tamoxifen: findings on transvaginal ultrasonography and magnetic resonance imaging

“…9,10 Therefore, a differential diagnosis is necessary for various polypoid tumors with endometrial thickening due to tamoxifen, including adenofibroma, endometrial polyp, endometrial hyperplasia, endometrial carcinoma, and gestational trophoblastic disease. [6][7][8]10,20 In our cases, the adenofibromas strongly resembled endometrial polyps not only on findings of MR imaging but also in terms of sonographic characteristics. Additionally, there was a resemblance between these benign lesions and endometrial carcinoma on transvaginal ultrasonography with respect to the sonographic appearance, which showed endometrial thickening and an echogenic mass with many small cysts in the uterine cavity.…”

“…It has recently been reported that adenofibroma on ultrasonography with color Doppler imaging is observed as an intracavitary mass containing multiple small cysts with low-resistance intratumor blood flow. 6 Color Doppler imaging shows lower impedance to blood flow in the uterine arteries in patients taking tamoxifen, confirming that tamoxifen can cause potentially malignant changes in the endometrium. 10 Microscopically, the arrangement of stromal cells in adenosarcoma is similar to that seen in adenofibroma.…”

“…3,5,7 Although the causal relation between tamoxifen and adenofibroma is not definitive, there have recently been reports on a relation between tamoxifen and adenofibroma. [6][7][8] However, the number of case reports remains small.…”

“…[14][15][16] The diagnosis of adenofibroma is usually made after hysterectomy, as the findings on endometrial curettage prior to hysterectomy are frequently inconclusive. 6 If adenofibroma is suspected in peri-or postmenopausal women, hysterectomy is the preferred treatment because of the high recurrence rate when it is incompletely curetted or resected. 3 In addition, hysterectomy ensures complete removal and permits thorough sampling to exclude a diagnosis of adenosarcoma.…”

Tumorigenic Effects of Tamoxifen on the Female Genital Tract

“…It most commonly occurs in postmenopausal women (Zaloudek and Norris, 1981). Five cases of uterine adenofibroma in a postmenopausal patient receiving tamoxifen were reported (Huang et al 1996; Oshima et al 2002; Hayasaka et al 2006). …”