Labial salivary gland tumors.

A study was conducted on labial salivary gland tumors from four oral pathology laboratories. Of the 103 identified tumors, 87 (84.5%) were from the upper lip, whereas 16 (15.5%) were from the lower lip. Of the 87 upper lip tumors, 80 (92.0%) were benign. Forty-three of these were monomorphic adenomas and 37 were pleomorphic adenomas. Seven malignant tumors of the upper lip were as follows: four adenoid cystic carcinomas, two acinic cell carcinomas, and one adenocarcinoma. Of the 16 lower lip tumors, 15 (93.8%) were malignant. Thirteen of these were mucoepidermoid carcinomas and two were acinic cell carcinomas. The only benign lower lip tumor was an intraductal papilloma. These results confirm the findings of previous investigations, showing that minor salivary gland tumors are much more common in the upper lip than the lower lip, but that lower lip tumors are more likely to be malignant.