Mucoepidermoid tumors of salivary glands. A long term follow-up study.

Mucoepidermoid tumors of salivary glands are relative rare and it has often been difficult to correlate the pathologic features and clinical aspects. The literature recommends long term follow-up studies. The object of the present study was therefore to follow this recommendation. The clinico-pathological features of 39 mucoepidermoid tumors are presented. The material was retrieved from the files of the pathological institute, Rigshospitalet, Copenhagen, during the period 1941-75. All patients, 24 males, 15 females, were followed for a minimum of 5 years. The lesions were classified into low grade (13 cases), intermediate grade (14 cases) and high grade (12 cases). The corresponding 5, 10 and 15 years cumulative survival rates were 92%, 92%, 92% for low grade, 47.4%, 47.4%, 35.5% for intermediate grade and 0%, 0%, 0% for high grade tumors. Thus we found a close correlation between pathology and clinical course. Furthermore, a 5 year observation period appeared an acceptable approach, because 17 of the 18 patients who succumbed of the disease, did so within 4 years following surgery. We consider all grades of mucoepidermoid tumors to be potential malignant. In our study one patient with a low grade tumor died of the disease.