Abstract
Basal cell adenoma (BCA) is a rare type of benign salivary gland tumor. It frequently occurs in the parotid glands but rarely in the minor salivary grands. We report a rare case of BCA of the buccal mucosa. A 81-year-old man presented to our department with a mass of his left side of buccal mucosa. Intraoral examination revealed an elastic-hard, mobile, well-circumscribed submucosal mass covered with normal mucosa, measuring about 15 mm in diameter. Ultrasonography showed well-defined hypoechoic area and slight blood flow. Clinical diagnosis was a benign buccal tumor. The tumor excision was performed under intravenous sedation. Since the tumor had distinct capsule and no adhesion with surrounding tissue, it was easily resected. Histopathological examination revealed that the tumor was encapsulated by thin fibrous connective tissue. Some tumor nests presented with
biphasic tubular structure composed of inner luminal cells and outer basaloid and myoepithelial cells. Immunohistochemical examination revealed that the basaloid and the myoepithelial cells were positive for p63 and the luminal cells and the stromal cells were positive for S-100. Ki-67 labeling index was less than 1%. Histopathological diagnosis was BCA. The postoperative course was uneventful. Tumor recurrence has not been observed over 3 years.