Hyalinizing clear cell carcinoma is a low-grade neoplasm of the minor salivary gland composed exclusively of epithelial cells and not myoepithelial cells. It predominantly affects the oral cavity of adult females. It is microscopically characterized by hyalinizing stroma and clear cells, which are typically positive for cytokeratin markers and negative for S 100 and smooth muscle actin (SMA). Cystic degeneration can also be present. Pathologists should be aware of this new entity so as not to misdiagnose otherwise. To our knowledge, this is the first case report of its kind from Malaysia.
The case of a minor salivary gland tumour, arising from the tongue, with nodal metastasis is presented. Biopsy of the tumour and fine-needle aspiration cytology of the neck swelling showed the presence of a clear cell carcinoma with evidence of nodal metastases. A commando operation was performed and the defect was reconstructed using a local tongue flap. The literature review indicated that the neoplasm was rare and its site of occurrence rather unusual.
Twelve pleomorphic adenomas of minor salivary gland origin were examined for the distribution of S-100 protein, detected using the peroxidase-antiperoxidase (PAP) method. Strong S-100 protein immunoreactivity was noted in areas containing plasmacytoid cells, stellate and spindle cells against a myxochondroid or hyalinous stroma, and solid epithelial areas. Tubular and duct-like structures showed variable stainability. Stromal tissue and normal salivary glands were generally negative for S-100 protein. These findings were compared with those reported elsewhere.