title: Extranodular background liver parenchyma of focal nodular hyperplasia: histopathological characteristics.
abstract: Focal nodular hyperplasia (FNH) of the liver is considered to develop as a hyperplastic response to a preexisting vascular abnormality. From the pathogenic point of view, we studied histological alterations in the extranodular background liver tissue of FNH (FNH-bg-liver). We compared ten FNH-bg-livers with ten non-FNH cases (non-FNH-liver) and found small uniform nodule formations with ring-like siderosis in the FNH-bg-livers (4/7, 57%) but not in the non-FNH-livers. Abnormal small arteries not accompanied by portal tracts were observed in six of six FNH-bg-livers for which immunohistochemical study was available, while this was observed in only three of the ten non-FNH-livers. CD34-positive sinusoids around the portal tracts were observed in only the FNH-bg-livers (3/6, 50%). Further, two of ten FNH-bg-livers had ectopic pancreatic tissue. Ring-like siderosis, abnormal small arteries, CD34-positive sinusoids, and ectopic pancreatic tissue were characteristic in the extranodular background liver tissue in cases of FNH.
authors.affiliation: Department of Pathology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka-shi, Saitama-ken, 350-1298, Japan.
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Murata
authors.forename: Michio
authors.initials: M
authors.lastname: Shimizu
authors.forename: Masanori
authors.initials: M
authors.lastname: Yasuda
authors.forename: Takaki
authors.initials: T
authors.lastname: Sakurai
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ban
authors.forename: Kohji
authors.initials: K
authors.lastname: Nagata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Seiya
authors.initials: S
authors.lastname: Sannohe
mesh_terms: D000328:Adult; D001158:Arteries / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D002828:Choristoma / Q000473:pathology; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006498:Hepatectomy; D006801:Humans; D007150:Immunohistochemistry; D008099:Liver / Q000098:blood supply / Q000473:pathology*; D008107:Liver Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010179:Pancreas; D012806:Siderosis / Q000473:pathology
chemical_list: D015415:Biomarkers