The role of immunohistochemistry in the diagnosis of hyalinizing clear cell carcinoma of the minor salivary gland: a case report

A case of hyalinizing clear cell carcinoma (HCCC) of the minor salivary glands of the oral cavity is reported. A 52- year-old woman presented with a growing mass at the base of the tongue. The patient underwent complete resection of the tumour. The histological picture was characterized by trabeculae or solid nests of proliferating cells with a clear cytoplasm, surrounded by a hyalinizing stroma. Tumour cells were immunoreactive for Cytokeratins 5, 6, 7, 8, 14, 17 and 18. No reactivity was observed for cytokeratin 20, vimentin, S- 100 protein, smooth-muscle actin, muscle-specific actin, and calponin. These findings confirmed the diagnosis of HCCC of minor salivary glands of the oral cavity. The clinical presentation, the immunohistochemical pattern and the role of cytokeratins in the differential diagnosis of HCCC are discussed with a review of the literature.