A malignant neoplasm which occurs mostly in the major salivary glands (most frequently in the parotid gland), but also in the minor salivary glands of the oral mucosa and the tracheobronchial tree. It is characterized by the presence of ductal structures which are lined by an inner layer of cuboidal epithelial-type cells and an outer layer of myoepithelial cells with clear or eosinophilic cytoplasm. [from
NCI]