Abstract
A 6-week-old boy presented to the emergency department with acute respiratory distress and vomiting. He was born full term without perinatal complications, but he had breathing problems while crying since birth. Three days earlier, he was brought to the emergency department for breathing difficulty. Findings on examination at that time were normal, and he was discharged.
At the return visit to the emergency department, the patient exhibited decreased breath sounds, intercostal retractions, distension of the abdomen, and tachycardia. His oxygen saturation level was 70%. He was intubated, and the otolaryngology service was consulted to evaluate the airway. He was taken to the operating room for direct laryngoscopy, which detected laryngeal edema and a mass at the base of the tongue that had completely obscured the vallecula and epiglottis (figure 1). Magnetic resonance imaging (MRI) confirmed the presence of a 1.3 × 1.1-cm simple unilocular cyst at the base of the tongue (figure 2). MRI also showed that the thyroid gland was normal.
Direct laryngoscopy shows the lingual thyroglossal duct cyst (arrow) at the base of the tongue.
The cyst (arrow) is seen on gadolinium-enhanced T1-weighted MRI.
The infant was returned to the operating room, where the mass was visualized through the laryngoscope and punctured with microscissors. It was then excised entirely by Bovie cautery. The patient's recovery was uneventful, and he was extubated within 24 hours without difficulty. Pathologic analysis of the specimen revealed a squamous epithelium-lined cyst consistent with a lingual thyroglossal duct cyst.
Thyroglossal duct cysts are the most common congenital cysts of the neck. They develop as a result of the persistence of the embryonic tract made by the thyroid gland during its descent from the foramen cecum at the base of the tongue to below the thyroid cartilage. While most thyroglossal duct cysts occur in the neck, about 2% are found at the tongue base.1,2
Burkart et al studied 16 children (mean age: 3 yr) with a lingual thyroglossal duct cyst (LTGDC) and reported that most of these cysts were found incidentally, although the range of presentations varied from mild discomfort at the base of the tongue to cyanosis, labored breathing, and respiratory distress. 3 Few cases of LTGDC causing acute respiratory distress have been reported to date. However, several instances of sudden infant death have been attributed to LTGDC-induced upper airway obstruction.1,4,5
The differential diagnosis of a tongue base mass includes dermoid, teratoma, vallecular cyst, lingual thyroid, lymphangioma, and hemangioma. 6 LTGDCs can be distinguished from most other lesions on direct laryngoscopy by their typical appearance as a midline mass located immediately posterior to the foramen cecum. After excision, a histologic finding of an epithelial lining without ectopic thyroid tissue confirms the diagnosis. 1 Imaging techniques are useful in defining the extent of the cyst and in determining the presence of a normal thyroid.
Regardless of whether the patient is symptomatic, LTGDCs warrant surgical excision because of their potential to become inflamed and cause airway obstruction. Several surgical approaches have been described to treat LTGDCs, including transoral marsupialization, cystectomy, and the Sistrunk procedure. 3
Among the 16 patients who underwent cystectomy in the study by Burkart et al, none exhibited any evidence of recurrence after a median follow-up of 3.7 years. 3 Cysts that do recur likely involve a more complex relationship with the hyoid bone, and affected patients may benefit from a modified Sistrunk procedure. 7