Cystic hygroma of the skull base.

Cystic hygroma is a benign developmental tumor formed by lymph vessels that occurs in 1 of 12000 individuals and presents most frequently in the head and neck. It is often difficult to manage because the tumor frequently envelopes nearby vital structures. Lesions that extend significantly above the hyoid are especially difficult to excise because of the complexity of achieving a complete excision. This article describes a series of 3 cases of cystic hygroma that presented in the head and neck and, on further investigation, were found to also involve the skull base. This anatomic location is exceedingly rare, and these 3 cases represent new and difficult challenges not previously discussed in the literature, to our knowledge.