The thyroglossal duct cyst [TDC, or thyroglossal tract remnant (TTR)] is a well recognized developmental abnormality which arises in some 7% of the population. As a consequence, it represents the most common type of developmental cyst encountered in the neck region. It typically presents as a mobile, painless mass in the anterior midline of the neck, usually in close proximity to the hyoid bone. Less often, TDCs may present with signs and symptoms of secondary infection, or with evidence of a fistula. While TDCs are most often diagnosed in the pediatric age group, a substantial minority of patients with TDCs are over 20 years of age at the time of diagnosis. The standard surgical approach to TDC, encompassing removal of the mid-portion of the hyoid bone in continuity with the TDC and excision of a core of tissue between the hyoid bone and the foramen cecum, dates back to the late 19th and early 20th centuries and is often referred to as Sistrunk's operation. Malignancy is rarely encountered in TDCs; when such rare tumors do develop (in the order of 1% or so of patients with TDCs), they usually take the form of either papillary carcinoma of thyroid origin, or squamous carcinoma.