Epithelial-myoepithelial carcinoma of the maxillofacial and sinonasal region: a systematic review of presenting characteristics, treatment modalities, and associated outcomes.

Epithelial-myoepithelial carcinoma (EMC) is a rare salivary gland malignancy. Controversy exists in the literature regarding the effectiveness of treatment modalities employed in the management of EMC. This systematic review was undertaken to understand the presenting characteristics of EMC and identify the most common treatment modalities and their associated outcomes, in order to help guide an evidenced-based approach to the algorithm of care. The MEDLINE (PubMed) and Embase databases were searched (up to February 23, 2022), and the review was performed in accordance with the PRISMA statement. Fifty-seven studies (51 case reports and six case series) describing 91 cases of EMC were included in this review. In the included studies, a slow-growing painless mass was the most common presenting clinical feature. EMC was most frequently treated with surgery alone (65%). Local disease recurrence occurred in 24% of the cases and metastatic disease in 11%. A positive surgical margin was found to be associated with a higher risk of recurrence (P < 0.001), while adjuvant radiotherapy was associated with a decreased risk of local disease recurrence (P = 0.034). Metastatic disease and multimodal therapy were found to be associated with decreased disease-free and overall survival (all P < 0.05). The current literature supports surgery with clear margins as the mainstay of treatment for EMC of the salivary and seromucous glands of the head and neck. In certain situations, radiotherapy may improve disease-free survival.

Mucoepidermoid carcinoma of upper aerodigestive tract: clinicopathologic study of 78 cases with immunohistochemical analysis of Dicer expression.

MicroRNAs (miR) are small noncoding RNAs that are predicted to regulate up to 30% of protein-encoding genes. miR maturation requires functional microRNA machinery, including the Dicer protein. We review our experience with mucoepidermoid carcinoma (MEC) and characterize the prognostic value of Dicer expression. Expression of Dicer was assessed in 78 MEC by immunohistochemistry. Dicer expression was scored semiquantitatively and relative to the internal controls: large excretory/striated ducts or basal/parabasal layers of normal squamous epithelium (mucosa). Dicer scores were then correlated with clinical and pathologic parameters. Dicer over- and/or under-expression were more commonly seen in high-grade MEC (83%) than in low/intermediate grade MEC (35%; p=0.002) and in stage III/IV MEC (80%) than in stage I/II MEC (41%; p=0.04). Abnormal Dicer expression correlates with high-grade and advanced stage, acting as a univariate predictor of poor disease-specific survival (DSS) in MEC. Age and stage were independent predictors of poor DSS on multivariate analysis. Abnormal immunoexpression of Dicer in aggressive MEC suggests a role for miR and miR machinery in tumor progression.