A rare case of thyroid metastasis occurring 27 years after initial diagnosis of breast cancer: A Case Report
TL;DR
A rare case of thyroid metastasis detected 27 years after the initial diagnosis of BC with subsequent pulmonary, cervical lymph node, and skeletal metastases, highlighting the importance of considering metastatic disease in newly detected thyroid nodules, even decades after the initial diagnosis of breast cancer.
Abstract
Introduction Breast cancer (BC) most frequently metastasizes to bone, lung, and brain, whereas thyroid involvement is rare. We report a rare case of thyroid metastasis detected 27 years after the initial diagnosis of BC with subsequent pulmonary, cervical lymph node, and skeletal metastases. Case Presentation A 72-year-old woman diagnosed in 1997 with stage IIA, ER-positive, PR-positive, HER2-negative invasive ductal carcinoma underwent modified radical mastectomy followed by adjuvant therapy. After 27 disease-free years, a thyroid nodule was detected. Fine-needle aspiration suggested malignancy, and total thyroidectomy was performed. Immunohistochemistry showed GATA3, ER, and PR positivity with negative HER2, TTF-1, and thyroglobulin, confirming metastatic BC. PET-CT revealed cervical lymph node, pulmonary, and skeletal metastases. The patient received ribociclib, letrozole, and denosumab, with a favorable response at one-year follow-up. Conclusion This case highlights the importance of considering metastatic disease in newly detected thyroid nodules, even decades after the initial diagnosis of breast cancer.