(1) Sclerosing pneumocytoma is composed of two types of cells, including surface cells similar to type II alveolar cells and interstitial polygonal cells as well as a mixture of solid, papillary, spongy angiomatous and sclerotic growth patterns, and its tumor cells are positive for TTF1 and EMA both on the surface and interstitial cells, which can be distinguished from Sclerosing pneumocytoma [7]. This evidence concerns the gene TTF1 and neoplasm.