Epithelial-Myoepithelial Carcinoma of the Lacrimal Sac and Literature Review of the Lacrimal System

Abstract

Background: Epithelial-myoepithelial carcinomas make up less than 0.1% of head and neck malignancies and are regarded as rare, low-grade malignant neoplasms of the salivary gland. They are thought to arise from intercalated ducts with histopathology showing a classic biphasic morphology of an outer layer of myoepithelial cells and inner layer of epithelial cells. These tumors most commonly occur in the parotid gland; however, rare cases have also been described in the nasal cavity, nasopharynx, subglottis, base of tongue, and the lacrimal gland.

Objective: To describe the clinical presentation, surgical management, and histopathology of the first reported case of lacrimal sac epithelial-myoepithelial carcinoma. To conduct a literature review of this malignancy, which is present in the lacrimal system.

Methods: Case report (n = 1) and literature review.

Results: We report a case of a 72-year-old man presenting with epiphora and a lacrimal sac mass with intranasal extension on imaging and nasal endoscopy. A combined endoscopic endonasal and open approach provided successful definitive treatment for final pathologic diagnosis of epithelial-myoepithelial carcinoma of the lacrimal sac, with orbital reconstruction and lacrimal stenting providing good cosmetic and functional results.

Conclusions: After PubMed database search for any case series or reports of lacrimal system epithelial-myoepithelial carcinomas, we believe this is the first documented case originating from the lacrimal sac. Although the histopathology of this tumor is distinct, unusual location and clinical presentation may pose significant diagnostic difficulties.

Keywords: endoscopic lacrimal surgery; epiphora; epithelial–myoepithelial; lacrimal sac; lacrimal tumor.

Figure 1.

Noncontrasted maxillofacial computed tomography: (A) axial bone window, (B) axial soft tissue window, (C) sagittal bone window, (D) sagittal soft tissue window, (E) coronal bone-window, and (F) coronal soft tissue window. CT depicts a soft tissue ovoid mass centered in the right nasolacrimal sac, measuring 2.1 × 1.6 × 2.4 cm. No evidence of orbital invasion, but there is extension into the nasal cavity via the nasolacrimal duct to the level of the inferior turbinate and maxillary sinus. Smooth bony remodeling is evident with erosion of the medial lacrimal bone. CT, computed tomography.

Figure 2.

A, Low power: a tumor with oncocytic (eosinophilic) cytoplasm and gland-like spaces is shown. B, Higher power: gland-like spaces with 2 layers of cells are shown.

Figure 3.

A, Luminal more eosinophilic epithelial cells and myoepithelial cells with more pale cytoplasm. B, p63 staining of myoepithelial cell components.

Figure 4.

A, Smooth muscle actin staining of myoepithelial cell components. B, Keratin 7 staining of luminal epithelial components stronger than myoepithelial component.