Figure 2.

Histological findings of large-cell neuroendocrine carcinoma (LCNEC). (A) The tumor cells proliferated forming loosely solid lesions accompanied by extensive necrosis [hematoxylin and eosin staining (H&E); magnification, ×100]. (B) The tumor cells were arranged in sheets without a defined border. Individual cells were large with a high nuclear/cytoplasmic ratio, severe atypia and prominent nucleoli. The cytoplasm was acidophillic and relatively ample. Numerous mitotic figures and apoptotic bodies were observed, as well as multiple, interspersed areas of necrosis. (H&E; magnification, ×400). (C-E) Immunohistochemical staining. The tumor cells were positive for (C) synaptophysin, (D) chromogranin A and (E) CD56 (original magnification, ×200).