A case of adenocarcinoma, not otherwise specified arising at the sublingual gland

Adenocarcinoma, not otherwise specified (NOS), is a malignant tumor occurring in the salivary glands without any histologically specific features of other salivary gland tumors. The incidence of adenocarcinoma NOS accounts for 16.8 % of all salivary gland malignant tumors, with the parotid gland being the most frequent site and only 1 % occurring in the sublingual gland. Here, we report a case of adenocarcinoma NOS arising in the sublingual gland. A 72-year-old Japanese male presented with a rapidly growing mass on the right side of the oral floor and underwent surgical treatment followed by adjuvant radiotherapy. The tumor was histopathologically diagnosed as high-grade adenocarcinoma NOS. No recurrence or metastasis was observed for 2 years after treatment.