Histologically, the characteristic double-layer structure is composed of inner vascular endothelial cells and outer myoepithelial cells, representing a tubule-like structure.[14, 15] The diagnosis should be distinguished from cystic carcinoma, mixed adenoma, and myoepithelial carcinoma.[16] On immunohistochemical staining, the inner epithelial cells show positivity for CK-7, and the outer myoepithelium shows positivity for smooth muscle actin and P63, among others. The gene discussed is KRT7; the disease is malignant myoepithelioma.