[1758] International Consensus Study on the Terminology and Diagnosis of Tumoral Intraepithelial Neoplasms (“Adenomas” and “Intracystic Papillary Neoplasms” of WHO-2010) of the Gallbladder

Volkan Adsay, Kee-Taek Jang, Nobuyuki Ohike, Jorge Albores-Saavedra, Pedram Argani, Noriyoshi Fukushima, Toru Furukawa, Ralph Hruban, Hiroshi Kijima, David Klimstra, Gunter Kloppel, Gregory Lauwers, Atsushi Ochiai, Juan Carlos Roa, Michio Shimizu, Benoit Terris, Giuseppe Zamboni, Yoh Zen, Takuma Tajiri, Olca Basturk, Burcu Saka, Nevra Dursun, Pelin Bagci, Michael Goodman. Emory University, Atlanta, GA; SMC, Seoul, Korea; SU, Tokyo, Japan; INCMN, Mexico, Mexico; Johns Hopkins University, Baltimore, MD; Jichi Medical University, Tochigi, Japan; Tokyo Women's Medical University, Tokyo, Japan; HU, Aomori, Japan; Memorial Sloan-Kettering Cancer Center, New York, NY; TUM, Munich, Germany; MGH, Boston, MA; NCCK, Kashiwa City, Japan; PU, Santiago, Chile; Saitama Medical University, Saitama, Japan; CH, Paris, France; UV, Verona, Italy; KCH, London, United Kingdom; TUHH, Tokyo, Japan

Background: The 7 types of tumoral intraepithelial neoplasms (TINs) of the gallbladder (GB) originally recognized by Dr.Albores-Saavedra in the AFIP fascicle, were recently regrouped in the WHO-2010 under 2 major categories of adenoma vs. intracystic papillary neoplasm.
Design: 28 selected examples of TINs were evaluated on a digital platform by 18 authors from 9 countries.
Results: There was overwhelming consensus that these were neoplastic lesions (except 1 case), and that they were distinct from conventional (non-tumoral) dysplasia. There was fair agreement on the degree of dysplasia and the presence of invasive carcinoma (κ: 0.36 and 0.35, respectively). However, the terminology was highly problematic. The number of different diagnostic names used per case ranged 4-13 (median 8), and in each case at least half of the authors did not use the WHO terminology, some citing the potential misunderstanding of the term intracystic giving the impression of a tumor arising within a cyst. Furthermore, when forced to use the WHO, there was no agreement on specific subcategories (κ: 0.01-0.19), and even more importantly, agreement on placing the cases into adenoma vs. intracystic papillary neoplasm categories was fairly poor (κ: 0.23), with >25% of the evaluators disagreeing with the others in 43% of the cases. The cell lineage, one of the bases of the WHO classification, also had poor agreement (κ: 0.17) as assessed in routine histology alone.
Conclusions: There is consensus on the neoplastic nature of GB-TINs, and fair agreement on the grade of dysplasia and invasiveness. However, as in TINs of pancreas and bile ducts, the growth patterns and cell lineages show significant overlaps, leading to great subjectivity and frequently precluding the reproducible application of WHO classification. A unifying terminology is needed, emphasizing their analogy with pancreatobiliary counterparts.
Category: Pancreas

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 128, Wednesday Afternoon


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