Mucoepidermoid carcinoma arising in a background of sialadenoma papilliferum: a case report.

Sialadenoma papilliferum is a rare tumor, primarily of minor salivary gland origin, first described by Abrams and Finck (Cancer 24:1057-63, 1969). It is both an exophytic and endophytic papillary lesion histologically resembling syringocystadenoma papilliferum of sweat gland. The tumor is considered benign although rare recurrent cases have been reported. Three cases of malignant transformation of sialadenoma papilliferum have been described in the literature. We report a high grade mucoepidermoid carcinoma arising in a background of sialadenoma papilliferum, at the base of the tongue, an unusual location for minor salivary gland neoplasms. Eleven months after excision and nodal dissection, there is no evidence of recurrence or metastasis.