Acinic cell carcinoma (ACC) usually arises in the parotid gland and rarely occurs in the minor salivary glands. In particular, ACC of the upper lip is extremely rare, and the incidence is 0.94% of all minor salivary gland tumors. ACC of the lips is rare. We report two cases of ACC involving the upper lips. The first patient was a 42-year-old woman with a 7 × 10 mm painless granulomatous mass in the upper lip. As a result of biopsy following a clinical diagnosis of inflammatory granuloma, the lesion was diagnosed as ACC. The lesion was excised surgically. The second patient was a 69-year-old man with an 18 × 30 mm painless mass in the upper lip. The clinical diagnosis was a low grade malignant tumor of the minor salivary glands, and the lesion was excised surgically. The pathological diagnosis of the tumor was ACC. The first case was characterized by solid / lobular and microcystic growth of intercalated ductal and vacuolated cells, whereas the second case showed a mixture of papillary-cystic and solid/lobular growth patterns of acinar and vascuolated cell types. Neither case has shown any evidence of recurrence or metastasis 4 years and 3 years after surgery, respectively.
