Abstract
A 57-year-old man was referred to our hospital because of a lump of his lateral neck region. Aspiration and intraoperative biopsies were performed to confirm the pathological diagnosis. The tumor showed a neoplastic epithelium arranged in a ductal or follicular pattern with papillary proliferation, and tumor cells were immunohistochemically positive for thyroglobulin. The pathological diagnosis was papillary thyroid carcinoma metastasis to a lymph node in the lateral neck region. Metastases were also observed in other lymph nodes in the submandibular region, and multiple metastatic foci were later found in the lungs and brain. Heavy ion radiotherapy was performed to extend the patient's life.