In 1951 Kirklin and co-workers1 reported a study of 986 cases of parotid tumor seen at the Mayo Clinic from 1907 to 1944. They found that a little more than 300, or roughly one-third, of the patients had received previous surgical treatment for their parotid tumors by the time they entered the clinic. A previous operation had been performed on 33% of the patients with mixed tumor, 28% of the patients with Warthin's tumor, 28% of the patients with simple cyst, 52% of the patients with mucoepidermoid tumor, 53% of the patients with adenocarcinoma, 44% of the patients with cylindroma, 73% of the patients with undifferentiated carcinoma, 50% of the patients with undifferentiated sarcoma, and 54% of the patients with squamous-cell carcinoma. In other words, in roughly onethird of the patients with benign parotid tumor and in approximately one-half to two-thirds of the patients with malignant parotid tumor previous