Intraductal papilloma arising from sublingual minor salivary gland: case report and immunohistochemical study.

Intraductal papilloma is a rare benign salivary gland tumor. This lesion is commonly observed in the duct of the minor salivary gland, predominantly in lip and buccal mucosa, but the case in the sublingual region is quite rare. This report shows a first case of intraductal papilloma developed in minor salivary gland of sublingual region. A 47-year-old Japanese male was referred to our hospital with painless submucosal nodule in the right sublingual region beside Wharton's duct orifice. The excised specimen was histologically diagnosed as intraductal papilloma of minor salivary gland, according to the microscopic finding of the papillary growth of ductal epithelium into the ductal space with fibrovascular core. Immunohistochemical study showed the tumor cells originated from ductal luminal cells because of positive Cytokeratin 18 and 7 staining in both types of cells.