Management of Parotid Gland in External Auditory Canal Carcinoma

Objective: Management of the parotid gland is always concerning because carcinoma of the external auditory canal (EAC) can directly invade the parotid gland and the lymphatics of EAC drains into the parotid node. We investigated the incidence of parotid node metastasis and direct parotid invasion in patients with carcinoma of EAC. Methods: Forty-nine patients were enrolled in this study. Among them, 35 patients had squamous cell carcinomas (SCCs) and 18 patients had adenoid cystic carcinomas (ACCs). A retrospective review of the surgical specimens was undertaken with specific reference to direct parotid invasion and parotid node metastasis. Results: Parotid node metastasis was noted only in two patients (5.7%) of advanced stage SCC (III and IV), whereas none of the ACC patients showed parotid node metastasis. Direct parotid invasion occurred only in 5 out of 35 patients (14.2%) only in advanced stage SCC (III and IV); however, it did occur in 8 out of 18 patients (44.4%) in all stages of ACC. Conclusion: In SCC of EAC, elective total parotidectomy is necessary only in stages III and IV to control occult parotid node metastasis and direct invasion. In ACC of ear, elective partial resection of the parotid gland to secure adequate safety margins is mandatory in all cases.