2021 年 156 巻 p. 41-46
Neck cystic masses of various causes are frequently encountered in otorhinolaryngological practice. Papillary thyroid carcinoma is also known to be associated with cystic cervical lymph node metastasis. Measurement of the thyroglobulin level in the cyst fluid is considered to be useful for the diagnosis. Herein, we report a case of cervical schwannoma that was initially suspected as a cystic lymph node metastasis secondary to a papillary thyroid carcinoma. A 49-year-old woman was diagnosed as having thyroid papillary carcinoma and cervical lymph node metastases. She was treated by total thyroidectomy and cervical lymph node resection. Three years after the operation, she developed a cystic mass in the upper left neck, which began to gradually increase in size. We resected this cystic mass in the upper neck under the suspicion that it was a cystic lymph node metastasis secondary to the papillary thyroid carcinoma, but histopathology of the resected specimen revealed the diagnosis of schwannoma.