Branchial cysts: congenital or acquired?

Branchial cysts are one of the commonest causes of neck lumps in the young adult. Their aetiology is the subject of some controversy, although available evidence suggests that they are derived from lymphoid tissue. We present two cases of branchial cysts, and emphasise the importance of excluding more sinister causes of neck lumps before excision, even when the clinical features suggest benign pathology.