Intra-oral minor salivary gland tumors: A pathological study of 131 cases in the Japanese population

Abstract

Abstract Objective Intra-oral minor salivary gland tumors are relatively rare. This study aimed to clarify the frequency and distribution of intra-oral minor salivary gland tumors in Japanese patients. Methods We retrospectively analyzed the histopathological records of 131 patients with minor salivary gland tumors that were surgically treated between 1967 and 2017 at a single institution. Results Of the 131 minor salivary gland tumors, 61 (47%) were benign and 70 (53%) were malignant. The male:female ratio was 1:1.8 for benign cases and 1:1 for malignant cases. Most of the tumors occurred in the palate, followed by the floor of the mouth. The most frequent minor salivary gland tumor was pleomorphic adenoma among benign tumors and adenoid cystic carcinoma among malignant tumors. The rarest minor salivary gland tumors were Warthin tumors and basal cell adenocarcinoma, accounting for only 0.8% of all cases. Conclusions The present study determined the incidence rates of these rare tumors.