[1568] Immunohistochemical Study of Maspin for Pancreatic Tumors: Is It Useful for Materials Obtained from Endoscopic Ultrasound Guided-Fine Needle Aspiration?

Tomoko Mitsuhashi, Hiroko Asamuma, Tsuyoshi Hayashi, Tadashi Hasegawa. Sapporo Medical University, Hokkaido, Japan

Background: Differentiating pancreatic invasive ductal carcinoma (IDC) from atypical glands of atrophic acini due to chronic pancreatitis (CP) is always challenging for pathologists. Maspin is known to have tumor-suppressor function and expressed in certain kinds of adenocarcinomas.
Design: Maspin and p53 expression in IDC, pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasia (IPMN), and CP is evaluated immunohistochemically to distinguish malignant glands from benign glands, using 20 specimens from endoscopic ultrasound guided-fine needle aspiration (EUS-FNA) and surgically resected materials [20 invasive ductal carcinomas, including PanIN and CP in the same specimens, and 15 IPMNs (10 IPMAs and 5 IPMCs)]. Maspin is evaluated as (2+), (1+), pseudo-positive (+-) and (-). p53 is evaluated as positive if distinct strong nuclear stain is seen.
Results: Maspin is (+) or (2+) in IDC (either nuclear or nuclear plus cytoplasmic) and in mucin producing slightly atypical carcinomatous glands. High grade neoplasms (PanIN 2 and 3, borderline IPMN and IPMC) are variably positive for maspin. Atrophic glands of CP and are (+-) or (-). p53 positivity is variable in IDC and adenocarcinoma derive from IPMN, and is negative even in lymph node-positive IDC. Maspin positivity is also recognized in EUS-FNA specimens as shown in Table 2.

Table 1. Expression of maspin and p53 in surgically resected specimens
Surgically resected specimensMaspin (2+/1+/+-/-)p53 positive
IDC100% (15/5/0/0)45%
IPMA100% (0/10/0/0)0%
IPMC(+boderline)100% (4/1/0/0)33%
PanIN100% (4/6/0/0)20%
CP0% (0/0/10/10)0%
Normal pancreas3%(0/0/1/29)0%




Table 2. Expression of maspin and p53 in EUS-FNA specimens
EUS-FNA specimensMaspin(2+/1+/+-/-)p53 positive
Adenocarcinoma100% (8/2/0/0)38%
IPMA100% (0/5/0/0)0%
CP0%(0/0/2/3)0%
Gastric foveolar epithelium0%(0/0/0/10)0%
Pancreatic ductal epithelium0%(0/0/0/15)0%
Pancreatic acinar cells0%(0/0/0/10)0%



Conclusions: Although the restriction of EUS-FNA specimens, maspin is a very useful marker to differentiate potential malignant glands from benign glands and is better than p53, when it is judiciously applied.
Category: Liver & Pancreas

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 211, Tuesday Afternoon

 

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