Mucoepidermoid carcinoma of the parotid gland: The Mayo Clinic experience

Objective: To determine clinical and histopathologic features of mucoepidermoid carcinoma of the parotid gland, specifically, the relation of tumor stage and grade and treatment type with clinical outcome. Design: Retrospective clinical and histopathologic review. Setting: Tertiary care medical center. Patients: From 1940 to 1994, 128 patients were treated at our institution for parotid mucoepidermoid carcinoma. Eighty-nine of these patients had their first treatment at our institution; these cases were chosen for retrospective clinical and histopathologic review. Intervention: A head and neck pathologist independently reviewed the pathology specimens. Main Outcome Measures: Age, symptoms, stage, treatment type, tumor grade, pathological features, disease progression, and survival. Results: Results of clinical staging were: T1 in 56 patients, T2 in 13, T3 in 1, T4 in 15, NO in 85, N1 in 2, and N2 in 2. No patient had N3 or M1 disease. All patients underwent parotidectomy with or without neck dissection. Seven patients received postoperative radiotherapy. Tumor grade was low in 43 patients (48%), intermediate in 40 (45%), and high in 6 (7%). Only 5 patients had disease progression (local recurrence in 4, regional recurrence in 4, and distant recurrence in 2). At latest follow-up (mean follow-up, 14.7 years), 64 patients were alive without disease, 1 was alive with disease, 2 had died of mucoepidermoid carcinoma, and 22 had died of other causes. The Kaplan-Meier estimated cancer-specific survival rates at 5, 1.5, and 25 years were 98.8%, 97.4%, and 97.4%, respectively. Conclusions: In our study, tumor grade and stage appeared to be less important than previously described. With adequate parotidectomy and appropriate neck dissection, patients with mucoepidermoid carcinoma of the parotid gland appear to do well, with few recurrences.