Schwannoma of the neck simulating a thyroid nodule.

A 31-year-old man is reported with the rare occurrence of a neurogenic tumor simulating a thyroid nodule. A growing nodule of the right neck was the only clinical symptom. Ultrasonography revealed a hypoechogenic nodule on the right side of the thyroid gland. Technetium (Tc)-99m pertechnetate showed a normal thyroid scintiscan. Due to ultrasonography-guided fine-needle aspiration biopsy, a schwannoma (neurilemmoma) was suspected. Surgical intervention removed the nodule and histology confirmed a schwannoma with Antoni A structures. To avoid unnecessary or inappropriate surgical intervention in cases of hypoechogenic nodules in connection with the thyroid gland, other nonthyroidal structures that may cause hypoechogenic patterns with ultrasonography should also be considered. The key preoperative investigations in such cases are ultrasonography and sonographically guided fine-needle aspiration biopsy.