Figure 3.

Histologic findings of the solitary mass. (A) At the periphery, tumor exhibited micropolypoid growth, and central coagulative necrosis existed in the cell cluster (H and E; original magnification ×100). (B) Several tumor cells showed marked cytologic atypia with large hyperchromatic nuclei, vesicular chromatin and prominent eosinophilic nucleoli (H and E; original magnification ×400). (C) The tumor showed extensive necrosis (upper) and invaded to bronchial mucosa and blood vessel (H and E; original magnification ×40). (D) Immunostaining for CD34 revealed strong and diffuse positivity of epithelioid cells and prominent cytoplasmic vacuoles and lumens (original magnification ×400).