A case of focal oral mucinosis of the hard palate

Abstract

We report a case of 77-year-old woman with focal oral mucinosis (FOM) arising in the hard palate. The patient had noticed a nodular mass 8 years earlier and over this period she felt that it had gradually grown. The mass was 20mm in diameter, painless, and had a smooth surface. Magnetic resonance imaging of the lesion revealed high signal intensity on T2-weighted images. Because biopsy suggested a benign non-epithelial tumor, the tumor was resected under general anesthesia. Histological examination showed that the lesion consisted of well-localized myxomatous connective tissue. The tissue was stained with alcian blue, which disappeared after hyaluronidase digestion, indicating an abundance of acidic mucopolysaccharides. The fibroblast-like cells with mucin retention were immunohistochemically negative for S-100 protein. Finally, a review of diagnoses of FOM is presented.