Fig. 5

Macroscopic and microscopic findings of the resected specimen. a A 12-mm yellowish papillary exophytic mass (arrow) distinct from the adjacent mucosa is observed in the remnant gallbladder (the remnant gallbladder is on the left side, and the cystic duct is on the right side). b The tumor consisted of atypical glandular epithelium with mild-to-severe dysplasia arranged in a high papillary architecture with thin fibrovascular stalks (hematoxylin–eosin (H&E) staining, × 40). c Biliary morphology with cuboidal cells showing clear to eosinophilic cytoplasm, enlarged nuclei, and prominent nucleoli (H&E, × 200). d Focal stromal invasion in the muscle is visible (arrow). (H&E, × 200)