# Epithelial-myoepithelial carcinoma of the nasopharynx: cases report and literature review

## TL;DR

This paper reports two rare cases of epithelial-myoepithelial carcinoma in the nasopharynx, highlighting their different outcomes and suggesting that high 18F-FDG uptake may indicate a more aggressive form of the disease.

## Contribution

The study contributes novel insights into the variable clinical behavior of nasopharyngeal EMCa and identifies potential biomarkers for aggressive disease.

## Key findings

- One patient achieved a complete clinical response with surgery and radiotherapy, remaining disease-free for 31 months.
- Another patient showed aggressive disease with high 18F-FDG uptake and required combined chemotherapy and immunotherapy for stabilization.
- The study suggests high 18F-FDG uptake may be a biomarker for aggressive EMCa.

## Abstract

Epithelial-myoepithelial carcinoma (EMCa) is a low-grade malignant tumor that occurs primarily in the salivary glands. Its occurrence in the nasopharynx is exceedingly rare. Due to its scarcity, there is currently a lack of standardized treatment protocols, and robust prognostic data remain limited.

We report a case series of two patients with histopathologically confirmed nasopharyngeal EMCa, supplemented by a systematic literature review to summarize its clinicopathological characteristics, treatment modalities, and prognostic factors.

The two cases exhibited strikingly divergent outcomes. The first patient (Case 1) underwent surgical resection followed by adjuvant radiotherapy, achieving a complete clinical response and remaining disease-free at 31 months. In contrast, the second patient (Case 2) presented a markedly more aggressive profile, characterized by younger age, neurological symptoms, and an atypically high 18F-FDG uptake on PET/CT, a notable deviation from the typically non-significant avidity reported for EMCa. Despite aggressive multimodal therapy, the disease progressed rapidly with extensive metastases. Subsequent institution of a combined chemotherapy and immunotherapy regimen successfully achieved disease stabilization.

Our cases illustrate the heterogeneous clinical behavior of nasopharyngeal EMCa, ranging from indolent disease to aggressive progression. Our observations suggest that high 18F-FDG uptake may serve as a critical biomarker for an aggressive phenotype. Given this variability, individualized treatment strategies may be warranted, and further studies are needed to better define optimal management for this rare tumor.