Intraoral Minor Salivary Gland Neoplasms: Review of 213 Cases

Abstract

Minor salivary gland tumors (MSGTs) constitute a heterogeneous group of neoplasms with great histomorphologic variation. This study reviews a large series of benign and malignant salivary gland tumors of the oral region and determines the incidence and the correlation of the histopathologic features with the clinical characteristics. Two hundred thirteen cases of MSGT were retrospectively studied. Hematoxylin-eosin-stained slides were examined in all cases. Special stains and immunohistochemical stains were used in selected cases. Clinical characteristics of the neoplasms were also noted. One hundred nineteen tumors were benign (56%), and 94 tumors were malignant (44%). Pleomorphic adenoma was the most common benign tumor (93 of 119). Canalicular adenoma was the second most common benign MSGT in our series (25 of 119). Of the 94 malignant MSGTs, mucoepidermoid carcinoma (MEC) (45 of 94), adenoid cystic carcinoma (22 of 94), and polymorphous low-grade adenocarcinoma (18 of 94) were the most common. Most MECs (34 of 45) were low-grade lesions. Of 5 central MECs, 3 cases occurred in the maxilla and 2 cases arose in the mandible. Benign intraoral MSGTs are slightly more common than malignant MSGTs. Pleomorphic adenoma is the most common MSGT, and MEC is the most common malignant variety. The palate is the most common site for minor gland neoplasms. Benign labial salivary gland neoplasms are more common in the upper lip, and malignant labial tumors are more common in the lower lip.