A, The spindle cells were entirely negative for CK. B, The majority of the spindle cells were positive for TTF-1. C, Diffuse and strong expression of EMA could be seen in the spindle tumor cells. D, Focally, expression of Actin(SM) could be seen in the spindle cells. E, The spindle cells also showed strong and diffuse expression of Vimentin. F, Less than 2% of tumor cells were positive for Ki67.