Cystic clear cell myoepithelioma of the parotid gland. A case report.

BACKGROUND: Myoepitheliomas of salivary glands are generally encapsulated, slowly growing asymptomic solid masses in which more than 50% are seen in the parotid gland. Cystic myoepitheliomas are very rare. CASE REPORT: We present an 80-year-old man with a cystic mass in the right parotid gland that had undergone superficial parotidectomy. In gross examination, a mass containing a large cyst was observed. Microscopically, tumor consisted of clear cells and small cuboidal cells, forming tubules in a hyalinized stroma. Immunohistochemically, clear cells were immunoreactive for S100 and smooth muscle actin. Cuboidal cells were positive for cytokeratin. Diagnostic and differential diagnostic criteria were discussed under the light of the current literature.