2023 Volume 50 Issue 6 Pages 409-416
The patient was a woman in her 50s. She was referred to our department with a diagnosis of papillary thyroid carcinoma. PET-CT performed for systemic search revealed a right breast mass with FDG accumulation and multi-organ metastasis, which was suspected to be an overlapping cancer with breast cancer. On palpation, a 1-cm-sized hard elastic mass was palpated just below the right nipple. Breast ultrasonography revealed an oval hypoechoic mass with a 10-mm diameter, smooth borders, and abundant blood flow at 6:00C section depth in the right breast. A needle biopsy was performed, and although the histological type was difficult to evaluate, a diagnosis of breast metastasis from papillary thyroid carcinoma was made based on immunohistochemical examination. Surgery was scheduled, but rapid progression of the disease was observed, and a total thyroidectomy and tracheostomy were performed urgently. Postoperative pathology diagnosed the thyroid tumor as anaplastic thyroid carcinoma, and although a final pathological diagnosis of the right breast mass was not reached, the diagnosis of breast metastasis from anaplastic thyroid carcinoma was considered appropriate given the rapid outcome and the findings consistent with a metastatic tumor on imaging. Breast metastasis from malignant tumors of other organs is extremely rare, and in this case, the definitive diagnosis of a breast mass was difficult to make. In addition to the imaging features of a metastatic breast tumor, it is important to consider the imaging features of the primary tumor and make a comprehensive judgment.
