Postoperative microscopical findings of lesion in the PSH portion. (A, B) The tumor shows papillary structures which are composed of hyalinized stalks lined with surface cuboidal cells which shows mild atypical nuclei with vacuolated and foamy cytoplasm. The sclerosing lesion contained round cells with uniform nuclei with pale, eosinophilic or clear cytoplasm. (C) On immunohistochemical stain, surface cuboidal cells were positive for pancytokeratin but round cells were negative for it. Both surface cuboidal cells and round cells were positive for TTF-1 (D) and negative for synaptophysin (E) and chromogranin (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 400 X).