Figure 2.

Bronchoscopic exam shows a whitish tumor obstructing the left upper bronchus. Gross. The tumor impacted the whole bronchus with clear margins. Microscopically, the biopsy specimen is composed of spindle cells with fibroblastic and myofibroblastic differentiation arrayed in fascicles. (A) The tumor is mostly limited within the bronchi. In a few foci, pushing of tumor margin to the lung parenchyma is noted (×20; ×100). Immunohistochemical study demonstrated (B) vimentin (+) (×200), and (C) cytokeratin (focal +), (×200).