Primary synovial sarcoma of thyroid: Diagnostic pitfalls and importance of immunohistochemistry.

Synovial sarcoma in the head and neck region is relatively uncommon, and primary synovial sarcoma of the thyroid gland is extremely rare with only 19 reported cases in the English literature. The rarity of disease leads to delayed and frequent misdiagnosis in the radiological and fine needle aspiration cytology examination. A prompt diagnosis is required to avoid emergency tracheostomy. An optimal immunohistochemistry panel with molecular evaluation is the cornerstone of diagnosis. We report a case of primary SS thyroid in a young male with detailed review of the literature.