Intraoral minor salivary gland tumors: a demographic and histologic study of 200 cases.

In a demographic and histologic study of 200 intraoral minor salivary gland tumors seen in Japan (Nagasaki and Miyagi prefectures), 127 cases (63.5%) were classified as benign, comprising 124 pleomorphic adenomas and 3 monomorphic adenomas. The other 73 cases (36.5%) were malignant tumors, represented by 33 adenoid cystic carcinomas, 16 mucoepidermoid carcinomas, 10 carcinoma in pleomorphic adenomas, 6 acinic cell carcinomas, 5 adenocarcinomas, one polymorphous low-grade adenocarcinoma, one undifferentiated carcinoma and one clear cell carcinoma. There was an overall female preponderance (1.78/1). The mean age for females was 47.2 years and for males was 50.6 years. The mean age for patients with malignant tumors was 10 years greater than for patients with benign tumors and was statistically significant. The palate was the most common site for intraoral minor salivary gland tumors followed by the lip and buccal mucosa. These three sites accounted for 83% of all cases. Tumors arising in these three sites were predominantly benign. In contrast, those located in the gingiva, floor of the mouth and tongue were predominantly malignant. The results of this study were compared with other recent studies.