Fig. 2

a, b Panoramic view of the pulmonary lesion showing uniform spindle cells arranged in a fascicular pattern; alveolar epithelium is focally entrapped by the neoplastic cells (H&E, 100×); c, d some small thinwalled blood vessels resembling spiral arterioles of late secretory endometrium were unevenly distributed among the stroma (H&E, 100×); b, d, neoplastic cells show moderate atypia and foci of hyaline-type necrosis, in a background of fibromyxoid stroma); d, the tumor cells had oval to plump spindle-shaped nuclei with finely granular chromatins, inconspicuous nucleoli, and amphophilic cytoplasms (H&E, 200×)