Basal cell adenoma of the minor salivary glands in the buccal mucosa: A case report and literature review

Abstract

Basal cell adenoma (BCA) is a relatively rare benign tumor of the salivary glands. However, BCA rarely occurs in the minor salivary glands. Herein, we report a rare case of BCA that originated in the left buccal mucosa of a 47-year-old female. Magnetic resonance imaging revealed a mass with a diameter of 1.5 cm and a well-defined periphery in a high-signal area on a T2-weighted image. The mass was located between the buccal and masseter muscles on the left side of the face. A biopsy was performed, and the results indicated a pathological diagnosis of BCA. Thereafter, excision of the mass was performed under local anesthesia. Histopathological examination showed that the tumor was covered with a fibrous capsule and filled with basal cell-like cells that proliferated in a solid, tubular, and trabecular pattern, with no cellular atypia or infiltrative growth. Immunohistochemistry analysis revealed that the tumor cells inside the luminal-tubular structure showed positive immunoreactivity for CK1/3, whereas those outside expressed αSMA and vimentin. However, most of the tumor cells were p63-positive. The Ki-67 labeling index of the tumor was 3%.In addition to this report, we present a review of cases of salivary gland tumors reported from 1991 to date. The review of the 20 cases (including the present case) indicated that the most common sites of occurrence were the upper lip and palate (7 [35%] cases), buccal mucosa (4 [20%] cases), and alveolar region (2 [10%] cases). The most common histopathological type was the solid type (12 cases).

Keywords

• Basal cell adenoma
• Minor salivary gland
• Immunohistochemistry
• Buccal mucosa