NCIt definition : An extremely rare, low-grade carcinoma that arises endobronchially in the central
airways. It is composed of small to medium-sized malignant epithelial cells with clear
and eosinophilic cytoplasm forming nests, cords, and trabeculae in a hyalinized stroma.
It is associated with the presence of EWSR1-ATF1 fusion gene.;