Follicular Variant of Papillary Carcinoma in Submandibular Ectopic Thyroid with No Orthotopic Thyroid Gland

Ectopic thyroid tissue with no orthotopic gland is extremely rare; malign transformation of ectopic thyroid is also an uncommon event, and rarer is the follicular variant of papillary carcinoma. In this clinical report, a case with submandibular ectopic thyroid without orthotropic thyroid gland is presented. Treatment was a complete resection of tumor, and histologic findings reveal follicular variant of papillary carcinoma. The patient had an uneventful postoperative recovery, and a substitution treatment with thyroxine was maintained. Physicians should be aware of the possibility that a lingual, submandibular, or lateral neck swelling could be an ectopic thyroid gland. This entity poses specific diagnostic and therapeutic difficulties, and definitive diagnosis is histologic. Computed tomographic scan, radioactive scan, and ultrasonography are necessary in revealing the presence of normal thyroid gland. Recommended treatment is primarily surgical, sometimes associated with radioiodine I 131 therapy and a substitution treatment with thyroxine.