title: A case of intrahepatic clear cell cholangiocarcinoma.
abstract: Intrahepatic clear cell cholangiocarcinoma is very rare - only 8 cases have been reported. A 56-year-old Japanese man with chronic hepatitis B infection was diagnosed with a 2.2 cm hepatocellular carcinoma on imaging, and hepatic segmentectomy was performed. Histopathologically, the tumor cells had copious clear cytoplasm and formed glandular structures or solid nests. These pathological findings suggested the tumor was a clear cell variant of intrahepatic cholangiocarcinoma. Particular stains and radiological images suggested that the cause of the clear cell change had been glycogen, not mucin nor lipid. On immunohistochemical staining, cytokeratin (CK) 7 and CK19 were positive, whereas CK20 was negative. Vimentin was detected on the cell membranes, and CD56 was focally positive. The patient was given adjuvant chemotherapy and is currently free from the tumor 7 mo postoperatively. Careful follow-up with adequate postoperative supplementary chemotherapy is necessary because the characteristics of this type of tumor are unknown.
authors.affiliation: Department of Pathology, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
authors.forename: Eo
authors.initials: E
authors.lastname: Toriyama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nanashima
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Kuniko
authors.initials: K
authors.lastname: Abe
authors.forename: Naoe
authors.initials: N
authors.lastname: Kinoshita
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yuge
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagayasu
authors.forename: Masataka
authors.initials: M
authors.lastname: Uetani
authors.forename: Tomayoshi
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D018262:Adenocarcinoma, Clear Cell / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D001653:Bile Ducts, Intrahepatic / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism; D018281:Cholangiocarcinoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007633:Keratins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D014746:Vimentin / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D014746:Vimentin; D007633:Keratins