Hyalinizing clear cell carcinoma of the base of the tongue.

Clear cell carcinoma of the salivary glands is a rare tumour that represents less than one per cent of all salivary tumours. They are divided into a biphasic, epithelial-myoepithelial carcinoma and a monophasic pattern which may be myoepithelial or ductal in origin. The latter is accompanied by prominent fibrohyaline stroma and has been described recently as hyalinizing clear cell carcinoma (HCCC). Most of the HCCC occur in the oral cavity, and are associated with minor salivary glands, unlike the biphasic pattern which is more common in the major salivary glands. In the oral cavity, the commonest site is the palate followed by the lips and the buccal mucosa. Its occurrence in the oropharynx and the larynx is extremely rare.