Epithelial-Myoepithelial Carcinoma of the Parotid Gland: A Report of a Rare Case and Review of Literature

TL;DR

This paper reports a rare case of epithelial-myoepithelial carcinoma in the parotid gland and reviews its characteristics and treatment challenges.

Contribution

The paper contributes a detailed case report and analysis of EMC, highlighting its rarity and treatment complexities.

Findings

EMC is a rare salivary gland tumor with distinct cell layers and specific staining markers.

Tumors with solid growth patterns and nuclear atypia tend to be more aggressive and prone to recurrence.

There is no standard treatment for EMC, but surgery and adjuvant therapies may be considered based on histopathological features.

Abstract

Epithelial-myoepithelial carcinoma (EMC) is a rare tumor, characterized by two different cell populations and both demonstrate a malignant nature microscopically. It constitutes less than 2% of all salivary gland malignancies. The World Health Organization (WHO) has classified this disease as a separate pathological category. The diagnosis of this tumor is arrived by biopsy. It shows slow growth and is small in size; it appears in ulcerative form of mucosa in some cases. Gland cells consist of two layers of outer myoepithelium cells and inner epithelial cells. Vimentin staining is positive. It shows calponin, muscle-specific actin, S100, smooth muscle actin, p63, and smooth muscle myosin heavy chain I. Examining different sets of data reveals that tumors exhibiting a solid growth pattern, nuclear atypia, DNA aneuploidy, and increased proliferative activity typically display a more aggressive nature, accompanied by a heightened likelihood of local recurrences and metastases. The clinical and radiological observations frequently resemble those of a benign tumor. Due to the uncommon nature of EMC, there is currently no established standard treatment protocol. It is considered a low-grade tumor where good resection holds better results. Individuals displaying histopathological indicators of aggressive disease should be evaluated for potential adjuvant radiotherapy. We present a case of a patient who had recurrence twice in a period of seven years despite surgical management, chemotherapy, and radiotherapy.

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