Epithelial-Myoepithelial Carcinoma: Insights From a Case Report.

Epithelial-myoepithelial carcinoma (EMC) is an uncommon malignancy that usually originates in the salivary glands. Its occurrence in the maxillary sinus is rare. We present a case of a 68-year-old male patient who has been experiencing swelling in the upper right back region of the jaw for the past three months. A computerized tomography scan of the paranasal sinus suggested the possibility of a malignant neoplastic mass originating from the right maxillary sinus, with significant local extension and bony erosions. Histopathology examination of EMC revealed a tubular morphology lined with inner luminal cells and outer clear cells of myoepithelial origin. For confirmatory diagnosis, immunohistochemistry (IHC) markers were applied, in which the inner lining of cells was positive for S100, while the outer lining of cells tested positive for both p63 and S100. The patient underwent a hemi-maxillectomy of the right side under general anesthesia.