Schwannoma (syn. neurilemoma, neuroschwannoma) is a benign tumor derived from nerve sheath cells (Schwann cells), which is the most common type of peripheral neurogenic tumors. In this case, a patient with papillary thyroid carcinoma on the left side was found to have a predominantly cystic nodule in the ipsilateral neck level 4 by ultrasonography (US), which mistook for ipsilateral cervical lymph node metastasis and was later found to be a vagal nerve sheath tumor by surgery. The article reviews the pathology, imaging findings and differential diagnosis of schwannomas. A meticulous evaluation and comprehensive differential diagnosis are pivotal to reach correct diagnosis.