Bronchoscopic management of a primary endobronchial salivary epithelial-myoepithelial carcinoma: A case report

Pulmonary Epithelial-Myoepithelial Carcinoma

Pulmonary epithelial-myoepithelial carcinoma (P-EMC) is an exceptionally rare subtype of salivary gland lung tumor originating from tracheobronchial glands. P-EMC is a biphasic tumor consisting of an inner layer of epithelial cells and an outer layer of spindle-shaped, clear-cell-like myoepithelial cells. Bronchial obstruction symptom is the main clinical characteristic for P-EMC. Because its clinical and imaging characteristics are highly similar to other types of non-small-cell lung cancer (NSCLC), it is easy to cause missed diagnosis and misdiagnosis. The diagnosis is mainly based on the pathology and immunohistochemistry with an inner layer of epithelial cells immunoreactive for cytokeratin and an outside layer of myoepithelial cells immunoreactive for S100 protein (S-100) and smooth muscle actin (SMA). Therefore, positive for cytokeratin, S-100 and SMA can assist in the diagnosis. Although in general, P-EMC is a low-grade malignant neoplasm, it may occasionally recur and metastasize. The optimal method for P-EMC treatment has not been established, and surgical resection is still the main clinical method. Radiotherapy and chemotherapy have been shown not sensitive for P-EMC treatment, whereas targeted therapy and immunotherapy have not evaluated in clinical practice. This review focuses on the pathological characteristics, molecular characteristics, diagnosis, treatment, and prognosis of P-EMC.

Primary salivary gland tumors of the lung: Two cases date report and literature review

Background

Primary salivary gland-type tumors of the lung (PSGTTL) is a rare intrathoracic malignant tumor that accounts for all lungs <1% of tumors.

Purpose

To introduce two case reports of primary lung salivary gland tumors, and highlight their diagnosis and treatment challenges.

Case report

The first case was a 30-year-old female, who complained of repeated coughing and dyspnea for 1 year and worsening for 2 days. Chest CT and bronchoscopy showed new organisms in the lower part of the trachea, that the bronchus obstruction accounted for 70%. The biopsy histology revealed a adenoid cystic carcinoma. She underwent extensive surgical resection and multiple radiotherapy, and She is recovering well from follow-up. The second case was a 70-year-old man, who complained of intermittent sputum blood for 2 years, worsening hemoptysis and chest tightness for 3 months. The new organisms was found in the upper trachea from Chest CT and bronchoscopy, and histological biopsy was used to diagnose epithelial myoepithelial carcinoma. He underwent twice bronchoscopy thermal ablation treatments. The follow-up is currently in good condition.

Conclusion

Primary lung salivary gland tumors are considered to be rare malignant tumors in the lungs. Early detection is advocated as late presentation with advanced tumor presents diagnostic and therapeutic challenges.