[362] Arginase-1: A Highly Specific Marker Separating Pancreatic Adenocarcinoma from Hepatocellular Carcinoma

Nazneen Fatima, Cynthia Cohen, Momin T Siddiqui. Emory University Hospital, Atlanta, GA

Background: The common developmental origin of the adult liver and pancreas has inspired investigation of the potential for hepatopancreatic precursor/stem cell persistence in liver and pancreas. Previous studies have demonstrated that Arginase-1 and HepPar-1 are effective immunohistochemical (IHC) markers for hepatocellular carcinoma (HCC). In this study we explored the possible efficacy of these stains in diagnosing pancreatic adenocarcinoma (PAD).
Design: Arginase-1 and HepPar-1 IHC was performed on formalin-fixed, paraffin-embedded fine needle aspiration (FNA) cell blocks (CB) of PAD (n=46), tissue microarray (TMA) of PAD (n=33), and FNA CB of HCC (n=44). Negative controls were also applied (PAD CB n=7, PAD TMA n=3, HCC CB n=35).
Results: PAD demonstrated Arginase-1 positivity in 0 of 46 cases and HepPar-1 positivity in 7 of 46 (15%) of CB's. PAD TMA demonstrated Arginase-1 positivity in 0 of 33 cases and HepPar-1 positivity in 4 of 33 (12%) of cases. HCC demonstrated Arginase-1 positivity in 37 of 44 (84%) cases and HepPar-1 positivity in 32 of 44 cases (72%).

Analysis of Arginase-1 and HepPar-1 in PAD CB and TMA
 Arginase-1 (CB)Arginase-1 (TMA)HepPar-1 (CB)HepPar-1 (TMA)
Sensitivity0%0%15%12%
Specificity100%100%100%100%
PPV0%0%100%100%
NPV13%8%15%9%




Analysis of Arginase-1 and HepPar-1 in HCC CB
 Arginase-1HepPar-1
Sensitivity84%72%
Specificity72%70%
PPV74%69%
NPV83%73%
Abbreviations: PPV, positive predictive value; NPV, negative predictive value


Conclusions: Both arginase-1 and HepPar-1 are effective IHC markers of hepatocellular differentiation. Arginase-1 demonstrates superior sensitivity and specificity compared with HepPar-1 in the diagnosis of HCC. However, despite the close relation between the liver and pancreas during embryogenesis, arginase-1 has a low sensitivity and a very high specificity for pancreatic adenocarcinoma. This finding is an important diagnostic tool in separating HCC from pancreatic adenocarcinoma, especially in specimens with small tumor samples.
Category: Cytopathology

Monday, March 4, 2013 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 49, Monday Morning

 

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