title: Immunostains Used to Subtype Hepatic Adenomas Do Not Distinguish Hepatic Adenomas From Hepatocellular Carcinomas.
abstract: Immunostains are used to subtype hepatic adenomas to stratify for the risk of malignant transformation. The most common panel of immunostains used for this purpose includes liver fatty acid-binding protein (LFABP), serum amyloid A (SAA) protein, C-reactive protein (CRP), and glutamine synthetase (GS). Importantly, some pathologists use these stains in an attempt to distinguish hepatocellular carcinomas (HCC) from hepatic adenomas. However, there are limited data on the performance of these stains in HCCs. To investigate the staining characteristics of HCCs, we studied 159 HCCs (92 well-differentiated, 67 moderately differentiated, and 7 poorly differentiated) and 7 fibrolamellar carcinomas for the expression of LFABP, SAA, CRP, and GS. All of the stains were positive in at least a subset of HCCs: SAA was positive in 27 of 159 (17%), CRP in 86 of 159 (54%), and GS in 23 of 47 (49%) cases; LFABP showed loss of staining in 36 of 159 (23%) cases. Fibrolamellar carcinomas were consistently CRP positive (7 of 7 cases) and frequently showed loss of LFABP (4 of 7 cases). There was no association between expression of SAA, CRP, and GS as well as loss of LFABP expression and other clinicopathologic features. HCCs with loss of LFABP were more frequently associated with negative GS expression (11 of 14 cases, P=0.02). These data show that immunostains used to subtype hepatic adenomas are not useful for distinguishing HCCs from hepatic adenomas and should be used only after a diagnosis of hepatic adenoma has been made using other criteria.
authors.affiliation: *Division of Anatomic Pathology, Mayo Clinic, Rochester, MN †Department of Pathology, University of California, Los Angeles, CA.
authors.forename: Liping
authors.initials: L
authors.lastname: Liu
authors.forename: Sejal S
authors.initials: SS
authors.lastname: Shah
authors.forename: Bita V
authors.initials: BV
authors.lastname: Naini
authors.forename: Samuel
authors.initials: S
authors.lastname: French
authors.forename: Tsung-Teh
authors.initials: TT
authors.lastname: Wu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Torbenson
authors.forename: Vishal S
authors.initials: VS
authors.lastname: Chandan
mesh_terms: D018248:Adenoma, Liver Cell / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor