[1556] CK17, MUC5AC, pVHL, and S100P Are the Effective Antibody Panel in Differentiating Intrahepatic Cholangiocarcinoma from Pancreatic Adenocarcinoma.

Fan Lin, Jianhiu Shi, Haiyan Liu, Jeffrey W Prichard, Hanlin L Wang. Geisinger Medical Center, Danville, PA; Cedars-Sinai Medical Center, Los Angeles, CA

Background: Distinction of intrahepatic cholangiocarcinoma (ICC) from ductal adenocarcinoma of the pancreas (DAP) can be very challenging or impossible based on the histomorphology alone. Many biomarkers have been studied in this regard. Unfortunately, no definitive markers have been reported. We have previously reported the diagnostic utility of CK17, MUC5AC, S100P, pVHL, maspin, and IMP3 in confirming the diagnosis of DAP and adenocarcinoma of the common bile ducts (Lin et al. AJSP 2008;32:78-91; Levy et al. Hum Pathol 2010;40:324-329; Lin et al. Modern Pathol 2010;23:363A, #1613). In this study, we attempt to explore the usefulness of this panel of antibodies in differentiating ICC from DAP.
Design: We immunohistochemically evaluated the expression of CK17, MUC5AC, pVHL, S100P, IMP3, and maspin on 30 cases of cholangiocarcinoma on routine histological sections and 70 cases of DAP (50 cases on tissue microarray sections and 20 cases of routine sections). The staining intensity was graded as weak or strong. The distribution was recorded as negative (<5% of tumor cells stained), 1+ (5-25%), 2+ (26-50%), 3+ (51-75%), or 4+ (>75%).
Results: The staining results are summarized in Table 1. Four of 5 CK17-positive ICC cases showed only focal positivity (1+). Six of 7 S100P-positive ICC cases were also negative for pVHL. Fourteen of 18 pVHL-positive ICC cases showed diffuse and strong positivity (3+ or 4+).

Table 1. Summary of the immunostaining results
AntibodyDAP (N=70)ICC (N=30)
CK1760% (42/70)17% (5/30)
MUC5AC67% (47/70)10% (3/30)
pVHL0 (0/70)60% (18/30)
S100P96% (67/70)23% (7/30)
Maspin100% (70/70)57% (17/30)
IMP390% (63/70)67% (20/30)

Conclusions: Our data indicate that CK17, MUC5AC, pVHL and S100P are the useful panel of antibodies in distinguishing intrahepatic cholangiocarcinoma from ductal adenocarcinoma of the pancreas.
Category: Liver & Pancreas

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 209, Tuesday Afternoon


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