Monophasic synovial sarcoma of the neck in an 8-year-old girl resembling a thyroglossal duct cyst.

Synovial sarcomas of the head and neck are rare. Typically, they are localized laterally in the parapharyngeal space. We report the case of an 8-year-old girl with a monophasic round cell synovial sarcoma of the anterior neck, clinically resembling a thyroglossal duct cyst. Histologic, immunohistochemic and cytogenetic findings are presented with a brief review of the literature. This case reaffirms the importance of considering malignant neoplasms in the differential diagnosis of pediatric neck masses.