Cystic and Papillary Neoplasm at the Hepatic Hilum Possibly Originating in the Peribiliary Glands

Figure 1

Case  1. (a) Contrast-enhanced CT shows a cystic lesion (arrow) (20 mm in diameter) at the confluence of the anterior and right bile duct with ring enhancement. There is no dilatation of the intrahepatic bile duct, except for slight dilatation of the proximal branches of the anterior branch of the bile duct. (b) The tumor (20 × 17 mm) is cystic and is filled with neoplastic cells and surrounded by a fibrous cyst wall (arrows). Loupe picture of the tumor (H&E staining). (c) Focal invasion of carcinoma is found in the fibrous capsule (arrow). Original magnification, 100x; H&E staining. (d) A papillary neoplasm composed of high-grade dysplasia with fine fibrovascular cores fills the cystic space of the tumor.  Fibrous capsule. Original magnification, 30x; H&E staining. (e) The papillary neoplasm is positive for MUC6. Original magnification, 100x; immunostaining for MUC6. (f) The invasive carcinoma in the fibrous capsule is positive for MUC6 (arrow). Original magnification, 100x; immunostaining for MUC6. (g) The peribiliary glands (nonneoplastic) adjacent to the tumor are also positive for MUC6. Original magnification, 100x; immunostaining for MUC6.

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