title: Primary hepatic tumors with myxoid change: morphologically unique hepatic adenomas and hepatocellular carcinomas.
abstract: Mucin production in primary liver neoplasms is typically interpreted as evidence for biliary differentiation. However, we have observed benign and malignant liver tumors that have abundant extracellular myxoid/mucinous material, yet have only evidence of hepatocellular differentiation. To further characterize these unusual findings, 9 cases were identified and further studied. Four cases were hepatic adenomas, whereas 5 were hepatocellular carcinomas. Extracellular myxoid/mucinous material was diffuse in 7 cases and patchy in 2 cases. The extracellular myxoid/mucinous material was typically weakly mucicarmine positive (N=6) and Alcian blue positive (N=8). All tumors were well differentiated, and none had evidence for biliary differentiation by morphology or immunohistochemistry. The hepatic adenomas arose in nondiabetic and nonobese patients. Both the hepatic adenomas and the hepatocellular carcinomas were strongly and diffusely HepPar1 positive, CK19 negative, and showed loss of LFABP protein expression. These findings indicate that extracellular myxoid/mucinous material in isolation should not be interpreted as cholangiocarcinoma. Furthermore, the unique morphology, the clinical characteristics, and the immunophenotype results suggest that myxoid hepatic adenomas and hepatocellular carcinoma may be unique tumor variants.
authors.affiliation: *Department of Pathology, Microbiology, and Immunology, Vanderbilt, Nashville, TN †Department of Pathology and Laboratory Medicine, Mayo Clinic, Rochester, MN §Department of Pathology, University of Washington School of Medicine, Seattle, WA ‡Department of Pathology and Microbiology, Saga University, Saga, Japan.
authors.forename: Safia N
authors.initials: SN
authors.lastname: Salaria
authors.forename: Rondell P
authors.initials: RP
authors.lastname: Graham
authors.forename: Shinichi
authors.initials: S
authors.lastname: Aishima
authors.forename: Taofic
authors.initials: T
authors.lastname: Mounajjed
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Yeh
authors.forename: Michael S
authors.initials: MS
authors.lastname: Torbenson
mesh_terms: D018248:Adenoma, Liver Cell / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D006528:Carcinoma, Hepatocellular / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000032:analysis; D010641:Phenotype; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D009077:Mucins