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The location, the slow growth, and the asymptomatic presence of this swelling are all common clinical presentations of the thyroglossal duct cyst. The age of the patient and the soft consistency of the swelling is not consistent with this condition; neither is the histology.
Thyroglossal duct cyst is an uncommon cyst. It arises along the embryonal thyroglossal tract, which is between the foramen cecum in the posterior tongue and the thyroid gland. Up to 80% occur below the hyoid bone. This cyst presents at any age, but is more common in young individuals; 50% occur in patients under 20 years of age. It is usually a firm, cystic mass in the midline. It is of variable size. It is usually asymptomatic and slow growing, but dysphagia may occur if it occurs in the higher portion of the tract. A fistula may also develop if it gets infected. It has a characteristic histological presentation of a cystic cavity lined by epithelium and supported by a connective tissue wall containing mucous secreting glands, thyroid follicles, benign lymphoid aggregates and others. Complete surgical removal is the treatment of choice; however, given the difficulty of removing the tract the lesion may recur and complete removal may be a challenge. The overall prognosis is good. The likelihood of recurrence depends on the completeness of removal. Squamous cell carcinoma within the lining epithelium has been described.