VP03.04: A rare case of uterine metastasis from breast cancer

Uterine metastases from breast cancer are uncommon and rarely reported in the literature. They occur preferentially in tumours with initial lobular carcinoma, initial lymph node involvement and positive hormonal receptors. We described the case of an asymptomatic 52-year-old woman who developed uterine and ovarian metastases two years after the diagnosis of an invasive ductal breast carcinoma with lymph node involvement and positive hormonal receptors. The patient received neoadjuvant chemotherapy, followed by left total mastectomy, axillary lymph node dissection and hormonal therapy. In her gynecological history, the patient reported a hysteroscopic myomectomy performed just after the breast surgery, and the finding of a new uterine fibroid during ultrasound examination performed after one year, with one episode of vaginal bleeding occurred 6 months before. Pelvic ultrasound examination performed during patient follow-up showed a submucous (G0-G1) myometrial lesion of 49x43x40 mm in size, with heterogeneous echogenicity, moderate vascularisation at colour Doppler and no acoustic shadows. The left ovary appeared with irregular margins, inhomogeneous echostructure and moderate vascularisation at colour Doppler. The ultrasound assessment was suspicious for an atypical myometrial lesion and possible ovarian metastasis. Total abdominal hysterectomy with bilateral salpingoophorectomy was performed. The anatomy-pathological examination and immunohistochemical staining revealed myometrial and ovarian metastases from lobular breast cancer. The particularity of our case is the myometrial metastasis. Metastases of breast cancer commonly involve ovaries, while the myometrium is rarely affected. The description of ultrasound features of uterine metastases may help for the correct preoperative diagnosis. Also, it may be useful for the differential diagnosis between primary uterine malignancy and uterine metastasis, as they benefit of different treatments.