A case of NR4A3-negative acinic cell carcinoma arising in the sublingual gland

Acinic cell carcinoma is a low-grade malignancy tumor and classified as a salivar y gland myoepithelial/basal cell non-associated tumor.Acinic cell carcinoma arising from the sublingual gland is very rare.In recent years, a number of specific genetic abnormalities of salivary gland carcinomas have been elucidated.NR4A3 is a diagnostic marker specifically expressed in the nuclei of acinic cell carcinoma.Here we report a case of acinic cell carcinoma that occurred in the sublingual gland, which did not express NR4A3, although it was histologically typical of acinic cell carcinoma.The patient was a 67-year-old man.He came to our department with the chief complaint of swelling in the floor of the mouth.A mobile mass with induration of 40 x 20 mm was observed in the left floor of the mouth.After obtaining a definitive diagnosis of acinic cell carcinoma by a biopsy, the patient underwent resection of the tumor and reconstruction with a cervical island skin flap.Histopathologically, the lesion showed the typical features of acinic cell carcinoma, but it was immunohistochemically negative for NR4A3.The postoperative course of the patient was excellent, and no recurrence or metastasis has been observed in the past five years.