Ancient schwannoma masquerading as a thyroid mass.

Schwannomas are benign, encapsulated nerve sheath cell neoplasms. Cervical sympathetic chain (CSC) schwannomas are rare, with less than 50 cited cases in the literature. CSC schwannomas may mimic a number of parapharyngeal masses. We report a rare variant, "ancient" schwannoma, which presented cytologically and radiologically as a thyroid mass. This is the first report of a CSC schwannoma mimicking a thyroid mass and the first report of an ancient schwannoma of the CSC.