Invasive ductal breast carcinoma metastatic to uterus

Abstract

Invasive lobular carcinoma (ILC) is the most common type of breast cancer that metastasizes to the uterus, whereas uterine metastasis from invasive ductal carcinoma (IDC) is very rare [1,2]. Metastatic characteristics also differ according to the histologic subtype of the primary cancer. Specifically, ILC usually forms small and diffuse nodal metastatic nests, while IDC usually causes relatively large metastatic foci [3,4]. A 66-year-old asymptomatic woman presented to our gynecologic outpatient department for a periodic follow-up examination after breast IDC. She had undergone radical mastectomy 10-years previously for primary left breast cancer (stage 1, grade 3). Pelvic examination revealed uterine enlargement resembling multiple subserosal myomas. Transvaginal ultrasound revealed a multinodular tumor with a low-echoic lesion inside, suggesting focal necrosis (Fig. 1). The only laboratory abnormality was cancer antigen (CA) 15-3 (101.8 μ/mL) and CA125 (131.4 μ/mL). Cervical and endometrial cytology tests were negative for malignancy. T1-weighted magnetic resonance imaging (MRI) showed a homogeneous iso-signal intensity mass located on the ventral side of the uterus; T2-weighted MRI revealed a homogeneous high-signal intensity mass with a higher-intensity area that coincided with the lowechoic lesion. Diffusion-weighted MRI (DWI) revealed hyperintense signals at the anterior and posterior sides of the uterus, while positron emission tomography (PET) indicated bifocal accumulation in the same locations (Figs. 2 and 3). A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. The tumor was located in the anterior wall of the uterus with vesicouterine extension where it infiltrated the myometrium and bladder wall. The omentum was strongly adhered to the tumor, but not in the context of widespread dissemination. Pathologic examinations, including hematoxylin–eosin staining and immunohistochemical staining for human epidermal growth factor receptor 2 (HER2/neu; + for primary and ± for uterine), estrogen receptor (both +), progesterone receptor (+ for primary and − for uterine), and cytokeratins 7 (both +) and 20 (both −) were performed. Except for the difference in the HER2/neu expression levels, the series of immunohistochemical staining studies revealed that the uterine and primary breast cancers shared the same ⁎ Corresponding author. Department of Gynecology, Shinsuma Hospital, Isonare-cho, Suma-ku, Kobe, Hyogo, 654-0047, Japan. Tel.: +81 78 735 0001; fax: +81 78 735 5685. E-mail address: funakikaoru@ybb.ne.jp (K. Funaki).