Duplicated facial nerve trunk with a first branchial cleft cyst.

First branchial cleft anomalies are rare and their various anatomical relationships to the facial nerve have been described. We encountered a 15-year-old female with a type II first branchial cleft cyst presenting as a right neck mass that we found during surgical excision to transverse two main facial nerve trunks. To our knowledge, this is the first reported case of a first branchial cleft anomaly in conjunction with a duplicated facial nerve trunk.