Benign giant-cell tumor of the common bile duct: A case report

Figure 3 Photomicrographs showing the general appearance of the tumor. A: Hematoxylin and eosin (HE) staining. A vague nodular pattern in the tumor and the normal surface epithelium of the common bile duct are observable. Note the infiltration into the wall; B: Mononuclear cells were mixed with multinucleated osteoclast-like giant cells. There was no cytologic atypia or mitotic figures, red-cell extravasation was present; HE staining; C: Tumor cells showing negative staining for CK19 compared with the remaining normal bile duct; D: Mononuclear cells and multinucleated giant cells showing strong cytoplasmic immunoreactivity for CD68; E: Granular cytoplasmic immunoreactivity for CD163 was restricted to the mononuclear cells; F: The mononuclear cells had an average Ki67 index of 10%-20%.