A Case of Thyroid Metastasis from Breast Cancer

Abstract

Thyroid metastasis from breast cancer is rare. A 51-year-old woman presented to us with a mass in the neck. She had been diagnosed as having hormone-positive breast cancer at 45 years old, and been treated by mastectomy, followed by chemotherapy and hormone therapy. Two years 4 months after the surgery, cervical lymph node metastasis was detected, and PET-CT revealed multiple metastases in the lymph nodes and sternum ; she was treated with an LH-RH analogue. Two years 11months after this therapy, a thyroid metastasis from the breast cancer was detected. She was administered chemotherapy, however, because of the emergence of severe adverse effects and at her urging, the chemotherapy was discontinued. For achieving local control while the chemotherapy was suspended, left thyroid lobectomy was performed. After the surgery, the patient was started on hormone therapy with tamoxifen and an LH-RH analogue. Subsequently, PET-CT revealed the presence of a metastasis in the right thyroid lobe, and chemotherapy was resumed.