Epithelial-myoepithelial carcinoma of the lung: a case report and literature review.

Epithelial-myoepithelial carcinoma (EMC), an uncommon neoplasm with low-grade malignancy, develops in tissues resembling those of the salivary glands. Pulmonary EMC (P-EMC) exhibits biphasic differentiation. The inner lining has epithelial-type cells, while the outer zone contains myoepithelial elements. This report describes the case of a 68-year-old man with P-EMC who presented with fever and a cough. Imaging revealed a pulmonary mass in the left lower lobe. Computed tomography revealed a mass with irregular borders and heterogeneous enhancement, suggesting a malignant tumor. The patient underwent radical surgery. Histopathological examination of the tumor revealed clear biphasic differentiation, including epithelial and myoepithelial cells. Immunohistochemical analysis demonstrated neoplastic cells expressing CK7, EMA, SMA, and p63, and negative for other lung cancer markers, leading to a diagnosis of P-EMC. The Ki-67 proliferation index was 30%, and no lymph node metastasis was detected. Additionally, we reviewed 46 published case reports on P-EMC. Although P-EMC has low malignant potential, accurate differentiation from other lung tumors and ongoing surveillance are essential for monitoring recurrence and metastasis. Early detection and timely intervention improves the prognosis.