Epithelial-Myoepithelial Carcinoma.

Epithelial-myoepithelial carcinoma is an uncommon low-grade salivary gland carcinoma. It is classically characterized by biphasic tubular structures composed of inner eosinophilic ductal cells and outer clear myoepithelial cells. In addition, epithelial-myoepithelial carcinoma sometimes shows various histologic features, including a cribriform pattern, basaloid appearance, and sebaceous differentiation. Because clear myoepithelial cells are also noted in other benign and malignant salivary gland tumors, the histologic variety and similarity with other tumor entities make the diagnosis of epithelial-myoepithelial carcinoma challenging. A recent analysis revealed that HRAS hotspot point mutations are specifically identified in epithelial-myoepithelial carcinoma and the assessment of given genes facilitate the correct diagnosis.