[1569] Significance of Obliterative Phlebitis for the Diagnosis of Lymphoplasmacytic Sclerosing Pancreatitis.

Katsuyuki Miyabe, Kenji Notohara, Takahiro Nakazawa, Tomoaki Ando, Kazuki Hayashi, Itaru Naitoh, Fumihiro Okumura, Michihiro Yoshida, Hirotaka Ohara, Takashi Joh. Nagoya City University Graduate School of Medical Sciences, Japan; Kurashiki Central Hospital, Japan

Background: Obliterative phlebitis is a useful pathological finding for the diagnosis of lymphoplasmacytic sclerosing pancreatitis (LPSP), or type 1 autoimmune pancreatitis. However, little has been discussed so far whether it is specific to LPSP among various pancreatic diseases.
Design: Resection or open biopsy specimens of LPSP (18 patients), chronic pancreatitis (CP; 24), and pancreatic ductal adenocarcinoma (PDA; 45) were gathered. In each case, serial sections were made from a representative block to stain H&E and elastica van Gieson (EVG). The number (/cm2) and diameter of obliterative venous lesion (OVL), which was defined as presence of inflammatory cells and/or fibrosis inside of tunica adventitia, were evaluated with EVG stain. Each OVL was classified into one of the 3 groups according to the histological findings seen in the affected veins; loosely-arranged lymphoplasmacytic infiltration and fibrosis (type 1), fibrosis and only a few lymphoplasmacytic infiltration (type 2), and densely-packed lymphoplasmacytic infiltration without fibrosis (type 3).
Results: Median number of OVLs in LPSP, CP, and PDA were 5.4, 1.0, and 2.6, respectively. Percentage of types 1/ 2/ 3 of OVLs was 86.2/ 6.8/ 7.0, 14.9/ 54.1/ 31.1, and 9.2/ 54.1/ 37.8 in LPSP, CP, and PDA, respectively. Type 1 OVL was observed in every case with LPSP, although it was less common in CP (5/24) and PDA (12/45) cases. In addition, veins with a diameter of 150μm or larger were affected in 36.2, 0, and 4.2% of type 1 OVLs in LPSP, CP, and PDA, respectively, and 17 out of 18 LPSPs had type 1 OVLs with a diameter of 150μm or larger. From receiver operator characteristic (ROC) analysis, cut off values of average diameter, maximum diameter, and number of type 1 OVL in each case for the diagnosis of LPSP were 84.5μm (sensitivity: 100%, specificity: 88.4%), 150.0μm (94.4%, 98.6%), and 1.6/cm2 (100.0%, 98.6%), respectively.
Conclusions: Although OVL itself is not specific to LPSP, type 1 OVL is more specific and frequently observed in larger veins in LPSP. We suggest that presence of type 1 OVL with a diameter of 150μm or larger is a highly diagnostic finding for LPSP.
Category: Liver & Pancreas

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 203, Wednesday Morning

 

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