Fig. 2.

Microscopic, morphological, and immunohistochemical findings.

(a) (b) In hematoxylin and eosin stain, these specimen were observed that the main pancreatic duct was dilated by mucous retention, and papillary tumor was increased in duct. Atypical cells with chromatin and irregular nuclear-to-cytoplasmic ratio was observed in pancreatic duct.

(c)(d)(e)(f)(g)(h)(i) Immunohistochemical analyses showed that the cells were positive for CDX2, MUC2,MUC5AC and, MUC6 and negative for MUC. Besides, immunohistochemical analyses showed that the cells were positive for Ki 67, and there was no overexpression for p53.