RESUMO
We report all year-old boy who presented with difficulty in swallowing without symptoms of hypothyroidism. The physical examination revealed a mass at the base of the tongue. The thyroid hormone profile showed a primary hypothyroidism (a serum TSH of 10.8 IU/mL with normal-low thyroxin of 6.0 fig/dL and low triiodothyronine of 57.8 ng/ dL). Antithyroid antibodies were negative. The fiberoptic endoscopy showed a reddish mass, without evidence of haemorrhage or ulceration, confirmed as a well circumscribed, hypodense mass in the base of the tongue by computed tomography of the oropharynx and neck. Tc-99-pertechnetate scanning showed an abnormal area of uptake at the base of the tongue and no uptake in the normal thyroid location, concordant with an ectopic lingual thyroid gland. Levothyroxine in a suppressive dose was started that resulted in a reduction of the size of the mass and disappearance of dysphagia.