Fig. 8

Macroscopic findings and histological findings of resected specimen. a Resected fresh specimen, proximal gallbladder identified as an accessory gallbladder containing carcinoma (single arrow), and distal gallbladder identified as a primary gallbladder (double arrows). b Formalin-fixed specimen, carcinoma in the proximal gallbladder identified as an accessory gallbladder (arrow). c, d Hematoxylin and eosin (H&E) staining at original magnification (× 20 and × 100). Pedunculated and non-invasive mucosal carcinoma had a fine stalk, and there was space between the mass and the gallbladder wall