A challenging entity for endocrine surgeons: Ectopic lingual thyroid gland. A case-based update

Introduction: Lingual thyroid (LT) is a rare embryologic anomaly. Diagnosis is challenging and treatment is still controversial. Case Report: We report a case of a 46 years old man with occasional sore throat, who underwent an otorhinolaryngology evaluation. Fiber optic flexible indirect laryngoscopy (FIL) highlighted a mass at the base of the tongue. Subsequent surgeon-performed neck ultrasound, computed tomography (CT) scan and thyroid scintiscan confirmed the diagnosis of LT. The patient had never investigated the thyroid before as he was totally asymptomatic. Subsequent blood tests revealed subclinical hypothyroidism. Fine needle aspiration (FNAC) showed benign cytology. After a multidisciplinary discussion, the patient was treated with suppressive doses of thyroxine due to subclinical hypothyroidism. At the follow-up the patient showed a size reduction of the ectopic gland at ultrasound and resolution of the initial symptoms. Conclusion: A comprehensive pertinent literature review was performed, showing few small series of patients affected by LT. Treatment options proposed for LT include thyroid hormone suppression therapy, radioactive iodine (RAI) ablation, and surgical excision. However, a consensus in management does still not exist so far. Most authors agree that no treatment is required when LT is asymptomatic and the patient is euthyroid. Thus, we proposed an update of the diagnostic and therapeutic algorithm for the management of LT based on the present cases. Further research regarding evaluation, monitoring and follow-up of ectopic thyroid tissue is necessary for better assessment of the workup and management of LT, in particular due to its possible but rare malignant nature.