Management of bilateral locally advanced squamous cell carcinoma of the external auditory canal

Abstract Bilateral squamous cell carcinoma (SCC) of the external auditory canal (EAC) is extremely rare. Here, we report the details of the history and management of a 74-year-old patient with bilateral locally advanced SCC of the EAC. The patient underwent subtotal temporal bone resection for primary SCC of the EAC in the right ear. Three years later, a biopsy revealed SCC of the contralateral ear. The patient received proton therapy for the second primary SCC of the EAC and achieved a complete response. Two years after proton therapy, a recurrence was observed in the left ear. Despite systemic chemotherapy for recurrence, the patient died of the disease. Although a second primary SCC in the contralateral ear is extremely rare, clinicians should consider the possibility of bilateral SCC of the EAC and carefully manage each of the ears during the follow-up period.