Fig. 2

Case 1: Histological findings of MiNEN in the gallbladder by hematoxylin and eosin (HE) staining. a Two components, LCNEC (right) and papillary adenocarcinoma (left) showed mixed composition and solid sheet distribution, with an obvious transitional zone between the two tissues. Magnification, × 100. b large cells arranged in solid sheets, with vesicular nuclei and abundant eosinophilic cytoplasm, and tumor cells had large-sized densely stained round to oval nuclei, in some cells visible nucleoli, high mitotic index (arrows), and focal tumoral necrosis consistent with LCNEC were showed. Magnification, × 400. c Metastatic lesion of the bile duct showing well-differentiated papillary adenocarcinoma. Magnification, × 100