Fig. 3.

Tumor characteristics. a Grossly, the 7-mm white mass along the posterior biliary duct was soft and non-encapsulated. b Histological findings on hematoxylin and eosin staining. The lesion consisted of dense lymphocyte infiltration with some lymph follicles. c and d Small to mid-sized lymphocytes formed lymphoepithelial lesions on some bile capillaries