Presentation on theme: "Intraductal Papillary Mucinous Neoplasm (IPMN) of the Pancreas: it’s Histopathologic Difference Between 2 Major Types Shinichi Ban, MD,* Yoshihisa Naitoh,"— Presentation transcript:
1Intraductal Papillary Mucinous Neoplasm (IPMN) of the Pancreas: it’s Histopathologic Difference Between 2 Major TypesShinichi Ban, MD,* Yoshihisa Naitoh, MD,* Mari Mino-Kenudson, MD, Takaki Sakurai, MD, Makoto Kuroda, MD,J Isamu Koyama, MD, Gregory Y. Lauwers, MD, and Michio Shimizu, MD*Am J Surg Pathol 2006, November ;Vol. 30: 1561–1569指導老師:方嘉郎；報告人:李俊志
2IntroductionIPMN is characterized by a predominantly noninvasive growth pattern with mucin production and cystic duct dilatation.The distinction between IPMN and pancreatic intraepithelial neoplasia (PanIN),which is the common precursor of invasive carcinomas
3Introduction 1999, Yonezawa Villous dark cell type--- resembles colorectal villous; MUC2 (+); intestinal typePapillary clear cell type--- resembles gastric foveolar epi. MUC (-); gastric typegastric type have not been fully described.
5IntroductionGOALS:Evaluate the distribution of the IPMNs and their derived invasive carcinomasRefine their differences of gastric-type and intestinal-type--- regard to their histopathologic characteristics and mucin profilesBetter characterize the gastric type
6Materials and Methods Patients’ data--- 80 cases: M/F(49/31) Mean age(65.3y/o, 37-83y/o);From1983 to 2003;from 4 hospitals (Saitama Medical School, Japan; Kyoto University Hospital, Japan; Fujita Health University, Japan, and Massachusetts General Hospital, USA)Exclusion: IPMNs of other type (ex:pancreatobiliary,oncocytic) and IPMN-like lesions
7Materials and Methods based on WHO classification on tumors of the digestive systeminternational consensus guidelines for IPMN and mucinous cystic neoplasms (MCNs)Gastric type--- clear/lightly eosinophilic; columnar; round to ovoid nuclei; no/minimal pseudostratifiedIntestinal type--- dark eosinophilic; columnar; oval to spindle nuclei; pseudostratified
8Materials and Methods Evaluation of 8 histologic features: distribution--- main duct or branch ducthistologic grade---benign/borderline/noninvasiveintraluminal nodular growthpyloric glandlike structureslow-grade PanIN-like complex within the tumor,atrophy of the surrounding pancreas tissuemucous lake formationoccurrence of invasive carcinoma.
9B. main duct-type IPMN A. branch duct-type IPMN intraluminal nodular growthatrophy of the surrounding pancreas tissue with fibrosismucous lakes devoid of neoplastic cells
11A. Pyloric glandlike: 2-3 glands lined by clear columnar epi A. Pyloric glandlike: 2-3 glands lined by clear columnar epi., located at the base of papillaB. PanIN-like complex: collection of small ducts lined by tall columnar mucinous cell
12Materials and Methods Mucin profiles (Semiquantitative) Extent of staining(extent score)--- 0(no staining), 1(<1/3 positive), 2(1/3-2/3 positive), and 3(>2/3 positive)intensity of staining (intensity score)---0(no staining), 1(weak), and 2(strong).labeling score--- extent score+ intensity score
13Results no significant difference between gender and age. Number GENDER: M/FMEAN AGEGASTRIC TYPE5031/1965.5 (47-83)INTESTINAL TYPE3018/1265.1(37-81)no significant difference between gender and age.
20Discussion Larger main duct-type (73%) + Rare (3%) (33%) high (50%) Intra-luminal nodular growthLow grade PanIN complexPyloric gland-likestructuregradeatrophy and fibrosisMucous lakeinvasiveIntestinal typeLarger main duct-type (73%)+Rare(3%)(33%)high(50%)7/30(23%)Gastric typeBranch duct-type(98%)rare(82%)(96%)low1/50(2%)
21DiscussionIntestinal-type IPMNs MUC2(+), whereas most gastric-type IPMNs are not.MUC5AC--- Both(+) in papilla, like organoid differentiation in stomach and pancreas.MUC6, both (+) ; more frequent in pyloric glandlike structures of gastric typeMUC1--- a marker for aggressiveness. both (-)--- IPMNs progress slowly
22Discussion Malignant change: intestinal >gastric Mucin pools --- associated with mucinous adenocarcinoma in intestinal-type IPMNs; lead to muconodular infiltration, like occurred in invasive colorectal villous tumors; sign of invasiveGastric-type IPMNs--- conventional type
23Discussion Gastric-type IPMNs V.S Low-grade PanIN Both have “pyloric gland-like structures” and “low-grade PanIN-like complex”Both are MUC5AC+/MUC2-Both have genetic alterantions associated with ductal carcinoma, ex: K-ras, p53, DPC4/Smad4, p16 (more common in Low-grade PanIN)Low-grade PanIN gastric-type IPMNsFurther molecular studies still needed
24Discussion Two hypothesis Gastric type, which being called “null-type” by Adsay et al, may progress to intestinal type or othersDifferent phathogenesis between the two types different mode of spreading through the pancreatic ductal systemGastric type --- low-grade PanIN-like complexIntestinal type --- involving small ducts with complete atrophy of surrounding parenchyma