title: CT of hilar cholangiocarcinoma: late contrast enhancement in six patients.
abstract: Hilar cholangiocarcinoma usually appears on CT scans as a low-density or isodense mass that abruptly obstructs converging dilated bile ducts. In four of six patients with histopathologically proved hilar cholangiocarcinoma who had late enhanced CT 8-15 min after dynamic CT, the lesion was seen as a high-density mass instead of the low-density lesion seen earlier on unenhanced and dynamic CT scans. The other two patients had ring enhancement with evidence of a thickened wall of the bile duct both on early and late enhanced CT scans. In the first four patients, carcinoma invaded the neighboring hepatic parenchyma and produced a mass, whereas in the last two, carcinoma was localized in the wall of the bile duct. Histopathologically, all lesions consisted of adenocarcinoma associated with a dense fibrotic tissue. As late enhanced CT shows hilar cholangiocarcinoma as a high-density mass, the exact location of the tumor and its relation to neighboring vessels can be determined, especially in relatively small tumors, and differentiation from sclerosing cholangitis is possible.
authors.affiliation: Department of Diagnostic Radiology, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takayasu
authors.forename: S
authors.initials: S
authors.lastname: Ikeya
authors.forename: K
authors.initials: K
authors.lastname: Mukai
authors.forename: Y
authors.initials: Y
authors.lastname: Muramatsu
authors.forename: M
authors.initials: M
authors.lastname: Makuuchi
authors.forename: H
authors.initials: H
authors.lastname: Hasegawa
mesh_terms: D002759:Adenoma, Bile Duct / Q000000981:diagnostic imaging*; D000368:Aged; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media