Sublingual contiguous thyroglossal and dermoid cysts in a neonate.

Thyroglossal duct cysts and dermoid cysts are two distinct lesions which can occur in the midline of the head and neck region. Different embryologic explanations for these two lesions have traditionally been accepted. Recent evidence, however, hints at an association between them. We present here a case in which both of these cysts occurred together in an unusual anatomic location, along with a discussion of the possible relationship between these two pathologic entities.