title: Arginase-1 is frequently positive in hepatoid adenocarcinomas.
abstract: Hepatoid adenocarcinoma is a rare extrahepatic tumor, which shows morphological and immunohistochemical similarities to hepatocellular carcinoma (HCC). Hence, hepatoid adenocarcinoma can cause diagnostic confusion with HCC. Arginase-1 immunostain has been recently shown to be an excellent marker of normal hepatocytes and is a sensitive and specific marker for HCC. However, the expression of Arginase-1 in hepatoid adenocarcinoma has not been evaluated in detail. Eight cases of hepatoid adenocarcinoma were immunostained with Arginase-1, Hepar-1, Glypican-3, CK7, CK20, CK19, polyclonal carcinoembryonic antigen, ɑ-fetoprotein, CDX2, and TTF-1. Albumin in situ hybridization was performed in 4 cases. All 8 cases were positive for Hepar-1. Arginase-1 was positive in 5 (62.5%) of 8 cases; 2 of these cases showed diffuse staining, while 3 showed patchy staining. Glypican-3, CK7 and ɑ-fetoprotein were each positive in 4 (50%) of 8 cases. CK19 was positive in 3 (37.5%) of 8 cases. polyclonal carcinoembryonic antigen showed canalicular staining in 3 (37.5%) of 8 cases and albumin in situ hybridization was positive in 3 (75%) of 4 cases. CDX2 was positive in 2 (25%) of 8 cases, both arising from the stomach. CK20 was positive in 1 (12.5%) of 8 case while TTF-1 was negative in all cases. Hepatoid adenocarcinoma has a similar immunostaining profile as HCC. Arginase-1 expression is common (62.5%) in hepatoid adenocarcinoma and hence it is not useful in distinguishing HCC from hepatoid adenocarcinoma.
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905. Electronic address: chandan.vishal@mayo.edu.
authors.forename: Vishal S
authors.initials: VS
authors.lastname: Chandan
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905.
authors.forename: Sejal S
authors.initials: SS
authors.lastname: Shah
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Torbenson
authors.affiliation: Division of Anatomic Pathology, Mayo Clinic, Rochester, MN 55905.
authors.forename: Tsung-Teh
authors.initials: TT
authors.lastname: Wu
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D000310:Adrenal Gland Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D001119:Arginase / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008113:Liver Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D008175:Lung Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012709:Serum Albumin / Q000235:genetics; D000075462:Serum Albumin, Human; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology
chemical_list: C422455:ALB protein, human; D014408:Biomarkers, Tumor; D012709:Serum Albumin; C574619:ARG1 protein, human; D001119:Arginase; D000075462:Serum Albumin, Human
keywords: Arginase-1; Glypican-3; Hepar-1; Hepatocellular carcinoma; Hepatoid adenocarcinoma; ɑ-Fetoprotein