Pulmonary epithelial–myoepithelial carcinoma without AKT1, HRAS or PIK3CA mutations: a case report

Abstract

Background: Pulmonary epithelial-myoepithelial carcinoma is a rare subtype of lung cancer. Because of its rarity, the molecular information on this carcinoma is insufficient. Case presentation: We report a case of pulmonary epithelial-myoepithelial carcinoma without AKT1, HRAS or PIK3CA mutations in a 76-year-old woman. Computed tomography revealed a tumor located in the left lower lung. Thoracoscopic left lower lobectomy was performed. Histopathologically, the tumor consisted of duct-like structures and polygonal and spindle cell features. The duct-like structures were composed of two distinct cell layers. The inner layer consisted of cuboidal cells that were positive for pan-cytokeratin and negative for p63, whereas the outer layer consisted of polygonal and spindle cells that were positive for p63 and weakly positive for pancytokeratin. We evaluated mutations in AKT1, BRAF, CTNNB1, HRAS, KRAS and PIK3CA but did not detect any mutations. Conclusion: Pulmonary epithelial-myoepithelial carcinoma is a rare subtype of lung cancer, with only 56 previous cases reported in the English literature. The genetic alterations in pulmonary epithelial-myoepithelial carcinoma are still unknown. We examined the 6 genes mutation analysis, however no mutation was detected.