Introduction/Background*Uterine metastasis from extravaginal cancers is a rare event. A few cases of lobular invasive carcinoma with endometrial metastasis was reported in the litterature.

Result(s)*A 40 year old woman was treated in 2015 for a localised synchronous bilateral invasive ductal breast carcinoma. Human epidermal growth factor receptor (HER2) was amplified with positive endocrine receptor. She underwent in 2015 a neoadjuvant sequential hemotherapywith trastuzumab, followed by bilateral mastectomy , adjuvant trastuzumab and hormonotherapy (Tamoxifene with chemical ovarian suppression). In 2020, the CT scan showedliver, bone and peritoneal metastasis associated with a retro uterine mass suggesting a cervical cancer as a second cancer.

A biopsie was performed and the morphological feature with immunohistochemistry concluded to a metastasis of ductal breast carcinoma : Gata 3 protein(+), ER + , PR+, HER2 overexpressed and Wt1 negative .

Conclusion*Although rare, intrauterine breast cancer metastasis can occur even with a ductal breast cancer and physicians must go for a biopsy with immunohistochemistry.