Familial occurrence of thyroglossal duct cyst.

Persistence and dilation of the embryologic thyroglossal tract gives rise to the condition of thyroglossal duct cyst. Although these cysts have an embryologic origin, there is rarely a history of inheritance. A search of the literature shows only two family reports, which includes a total of nine patients. We report on a third family with thyroglossal duct cyst in two members. The patients were female siblings aged 2 and 6 years, both of whom underwent successful surgical excision of their thyroglossal duct cysts by modified Sistrunk's technique.