Adenoid cystic carcinoma of the external auditory canal

Abstract

Adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) is rare, and so protocols for its treatment and management have not yet been established. We analyzed the treatment modalities used and the outcome of 5 patients with ACC of the EAC treated between 1997 and 2014, including 1 man and 4 women. The mean age of the patients was 51.4 years (range, 27 to 67 years). Ear pain was the most common complaint, observed in 4 of 5 patients. The clinical stage according to the Pittsburgh staging system was T1 in 3 patients, T2 in 1 patient, and T4 in 1 patient. Lymph node metastasis was observed in the 1 patient with T4 stage tumor. All the patients underwent surgical treatment. The 3 patients with T1 stage tumors and the 1 patient with T2 stage tumor underwent lateral temporal bone resection. The 1 patient with T4 stage tumor underwent subtotal temporal bone resection, total parotidectomy, and neck dissection, as well as postoperative adjuvant radiotherapy owing to the advanced T and N stages. All patients were pathologically confirmed to have a tumor-free margin. None of the 5 patients developed local recurrence, but the 1 patient with T4 stage tumor developed pulmonary metastases 37 months after surgery. Thus, early diagnosis is important and the possibility of malignant neoplasms should be considered while evaluating patients with continuous ear pain. En-bloc resection with wide local margins is useful to cure ACC of the EAC. Postoperative adjuvant radiotherapy can be used for patients with advanced T-stage tumors, but may not be necessary for patients with early T-stage tumors resected with a negative margin.