Diagnosis and differential diagnosis of branchial cleft cysts by CT scan.

The author stresses the importance of CT scanning in diagnosing branchial cleft cysts (BCCs) and in differentiating them from other cystic masses of the neck and parotid region. The CT examinations of 40 patients with neck or parotid cystic lesions suspected of being BCCs have been reviewed and correlated with the histological diagnosis. Sixteen BCCs (12 of the second and 4 of the first cleft) and 24 BCC mimics were evaluated. A definitive CT diagnosis of second BCC was possible in 83% of the cases. Exclusion of this diagnosis was possible in 94% of BCC mimics. The total accuracy of CT was 90%. Differentiation of first BCCs from their mimics is more difficult. Most first BCCs are located juxta-parotidal and at the lower pole of the parotid gland.