Sinonasal epithelial-myoepithelial carcinoma: Report of a novel subsite and review of the literature

Abstract

Background: Epithelial-myoepithelial carcinoma (EMC) is a rare tumor of the major and minor salivary glands. Sinonasal EMC is extremely uncommon and hitherto not described within the frontal or ethmoid sinuses.

Objective: To present a novel sinonasal subsite and review the literature regarding sinonasal EMC.

Methods: A case of frontoethmoidal EMC was presented. A medical literature data base was queried from January 1, 1950, to August 8, 2017, for all reports of sinonasal EMC.

Results: A 69-year-old man underwent combined open and endoscopic craniofacial resection of a right frontoethmoidal EMC, a previously undescribed primary location for this tumor. A comprehensive review of the literature revealed 13 additional cases of sinonasal EMC.

Conclusion: EMC is an uncommon neoplasm typically found in the major salivary glands; occurrence in the nose or paranasal sinuses is extremely rare. EMC often follows an indolent clinical course, although, in a minority of cases, particularly in large tumors with nuclear atypia, more aggressive behavior may be observed.

Figure 1.

Preoperative imaging. (A) Computed tomography, demonstrating a mass in the right anterior ethmoid sinus, with thinning of the lamina papyracea. (B) Sagittal T1-weighted magnetic resonance image, showing this mass as well as associated frontal sinus obstruction.

Figure 2.

Epithelial-myoepithelial carcinoma. (A) A specimen, demonstrating a densely cellular, multinodular lesion amid background salivary gland tissue (hematoxylin and eosin, original magnification ×20). (B) A specimen, demonstrating small ductal structures within the lesion (hematoxylin and eosin, original magnification ×200). The inner layers of cells are columnar, with granular eosinophilic cytoplasm; surrounding these are layers of cells with indistinct borders, vesicular nuclei, and clear-cell changes in a subset. There is little cytologic atypia or appreciable mitotic activity in either population. (C) Epithelial inner lining cells (pan-cytokeratin immunostain, original magnification ×200). (D) A smooth-muscle actin immunostain is positive in the surrounding myoepithelial cells (smooth-muscle actin immunostain, original magnification ×200).

Figure 3.

Frequency of presenting symptoms of sinonasal epithelial-myoepithelial carcinoma.

Figure 4.

Site of tumor origin.