Figure 1
From: Primitive neuroectodermal tumor (PNET) of the lung in an adult woman
Biopsy specimen from primitive neuroectodermal tumor (PNET) of the lung. (a) Areas of highly cellular neoplastic tissue (H&E, magnification × 40), (b) discohesive growth of small, blue, round to oval cells, characteristic of pulmonary PNET (H&E, magnification × 200). (c) Characteristic scant, basophilic cytoplasm, ovoid or polygonal nuclei, fine granular chromatin texture and marked nucleoli. Some nuclei were hyperchromatic. H&E, magnification × 400. d) CD99 membranous expression, characteristic of PNET (magnification × 100). and expression of (e) CD56 (magnification × 100) and (f) vimentin (magnification × 100). (g, h) Fluorescent in situ hybridization of EWSR1 gene: fusion signals: yellow or red/green double spot indicates intact EWSR1, separate green and red signals indicate translocation. Magnification (g) × 600, (h) × 1000).