Anaplastic carcinoma in submandibular region: A diagnostic dilemma

INTRODUCTION: Thyroid carcinoma arising in an extrathyroid area is a rare entity. PRESENTATION OF CASE: We report a case of anaplastic carcinoma in the submandibular region occurring in a 70-year-old woman. DISCUSSION: The location of the mass along with no evidence of primary tumor at the orthotopic thyroid gland posed a diagnostic dilemma: was this an ectopic thyroid carcinoma or rather a case of occult differentiated thyroid carcinoma metastasis that transformed to anaplastic carcinoma? Based on the histopathological findings we concluded that the tumor arised in ectopic thyroid tissue. Although the mass was completely resected, the patient died 10 months after diagnosis due to pulmonary metastases. CONCLUSION: Conclusively, the possibility of ectopic thyroid tissue, with or without disease, should be considered in cases of a mass in the submandibular region.