Concurrent papillary and squamous carcinoma in a thyroglossal duct cyst: a case report.

Carcinomas of thyroglossal duct cysts are rare. Most are papillary carcinomas; only about 5% are squamous cell carcinomas. Only one case of mixed papillary and squamous cell carcinoma of a thyroglossal duct cyst has been reported so far. The authors present a second case, that of a 38-year-old man who was first seen with a midline neck lump. It was diagnosed clinically as a thyroglossal duct cyst and was locally excised. Pathological examination showed both a concurrent papillary carcinoma and a squamous cell carcinoma. Treatment consisted of a near-total thyroidectomy, ablative radioactive iodine and adjuvant external radiation therapy. The authors review the literature and explain the rationale behind their choice of treatment.