Background: Carcinoma arising in a thyroglossal duct cyst is a rare entity. Malignancy generally is revealed only after surgical excision of a thyroglossal duct lesion because of the lack of specific physical findings.
Case: A 68-year-old male presented with a squamous cell carcinoma arising in a midline cyst in the neck. The malignancy had been discovered because of an enlarged metastasized lymph node in the left side of the neck. Fine needle aspiration cytology (FNA) showed cells with marked nuclear atypia and keratinizing cells.
Conclusion: To our knowledge, this is the 10th squamous cell carcinoma reported and, among these, the first case diagnosed preoperatively by FNA cytology. A firm diagnosis at the preoperative stage is important with this neoplasm to plan extensive surgical intervention.