Squamous cell carcinoma in a thyroglossal duct cyst: A case report with review of the literature.

Carcinoma arising within a thyroglossal duct cyst (TGDC) is exceedingly uncommon, occurring in about 1% of TGDC (Chrisoulidou et al., 2013 [1]). Since the first description of TGDC carcinoma in 1911 by Brentano, approximately 200 cases have been reported in the world literature, mostly as single case reports making its true incidence difficult to determine (Hanna, 1996 [2]). There are numerous reports in the literature of papillary and follicular TGDC carcinoma, but only limited reports of squamous cell carcinoma. In order for a lesion to qualify as squamous cell carcinoma of a TGDC, the lesion must arise from the epithelial lining. Recognition and understanding of this entity are important in staging and planning of treatment. Exclusion of primary squamous cell carcinoma arising from an adjacent structure or metastatic central compartment nodal disease is important in the evaluation for diagnosis to be confirmed. A thorough work up should be undertaken to exclude other primary malignancies that may have metastasized. We present a unique case of squamous cell carcinoma, along with supporting pathology and radiology imaging. We then review this rare entity and provide some insight into the diagnosis and management.