Postoperative microscopical findings of lesion in the carcinoid portion. (A) The tumor showed trabecular arrangement. (B) The tumor composed of monotonous small ovoid to spindle cells with “salt-and pepper” chromatin pattern without mitosis. The tumor cells were positive for CD56 (C), synaptophysin (D), chromogranin (E), but negative for TTF-1 (F). (A. Original magnification of H&E staining at 20 X; B. Original magnification of H&E staining at 400 X; C-F. Original magnification of immunohistochemical staining at 200 X).