Fig. 6

Histopathological findings. a, b Slightly elevated lesions consisting of dilated muscular arteries are seen in the gallbladder wall (black arrow) with ulceration of the overlying mucosa (blue arrow). In such lesions, focal disappearance of the internal and external elastic lamina (red arrow) and fibrinoid degeneration of the media (yellow arrow) are found in the muscular artery of the gallbladder wall (c–e). (a, b H&E stain; magnification × 40, c H&E stain; magnification × 100, d Elastica van Gieson stain × 100, and e Masson’s Trichrome stain × 100). H&E, hematoxylin and eosin stain