First branchial arch cyst in an elderly patient: diagnostic dilemma and subsequent management

The branchial system plays a significant role in the embryological development of the many internal and external human body structures. Failure of normal development of these systems may result in branchial system anomalies. Anomalies of the first branchial cleft are rare and account for 1-8% of all branchial anomalies. They have an incidence of 1 per 1 million births, most of which are diagnosed in early childhood. We present an unusual case of a first branchial arch cyst in an elderly gentleman: a 65-year-old man who presented with a persistent swelling in the left pre-auricular region with no associated sinus, fistulae or lymphadenopathy and with an intact facial nerve. Investigations including fine needle aspiration, ultrasound and magnetic resonance imaging led to the diagnosis of a lesion of salivary origin and an extracapsular dissection was undertaken. The histological appearance on excision was, however, in keeping with a first arch branchial cyst. In conclusion, the nonspecific clinical and radiological presentation of first branchial arch anomalies may lead to difficulty and often delay in the diagnosis of these lesions, particularly in elderly patients as it is more often associated with childhood and adolescence. A high level of suspicion is mandatory to prevent inappropriate management in the form of incision and drainage, which further increases the risk of recurrence and facial nerve injury at the time of formal excision due to scarring.