Acinic cell carcinoma arising in minor salivary gland of the upper lip

Acinic cell carcinoma is a rare malignant salivary gland tumor. This tumor most often occurs in the parotid gland of women and its occurrence in the minor salivary gland of men is rare. The typical clinical finding is that this tumor is a slow growing asymptomatic mass. Here, we report a case of a rapidly growing acinic cell carcinoma arising in the upper lip of a 44 year-old man. The lesion was surgically resected without extracapsular spread. Histopathologically, the cells had differentiated into serous acinar cells and displayed numerous variably sized cystic structures with papillary formation. Immunohistochemically, the Ki-67 labeling index was approximately 10%. These examinations indicated that the present case of this report could be diagnosed as acinic cell carcinoma with a papillary-cystic growth pattern.