Squamous cell carcinoma arising from a thyroglossal duct cyst: A case report and review of the literature.

Objectives: Squamous cell carcinoma in a thyroglossal duct cyst is exceedingly rare with only 26 reported cases in the literature so far, which only account for 6% of the patients.

Methods: We report a unique case of squamous cell carcinoma arising from a thyroglossal duct cyst in a 49-year-old male who was primarily diagnosed as a thyroglossal duct cyst with inflammation. The patient underwent Sistrunk procedure with wide local excision and radiation therapy as well as chemotherapy post-operatively and had no evidence of recurrence or metastasis for 24 months. In addition, we reviewed the relevant literatures.

Results: Whether squamous cell carcinoma actually arises from thyroglossal duct cyst is still controversial; however, carcinoma originating from metaplasia of columnar and squamous epithelium in thyroglossal duct cyst has been well accepted. The gold-standard diagnostic method is fine needle aspiration biopsy with ultrasound guidance. Sistrunk procedure alone or with wide excision is likely to be beneficial. Neck dissection is necessary in patients with positive cervical lymphadenopathy. Radiation therapy and chemotherapy have not yet been clearly defined.

Conclusion: Squamous cell carcinoma arising from thyroglossal duct cyst is really a rare disease, whose origin, treatments and prognosis still remain uncertain. These are solely based on case reports, case series and expert opinions. Hence, more investigations about squamous cell carcinoma will be conducted in the near future.