title: Usefulness of KL-6 in the subtyping of intraductal papillary mucinous neoplasia of the pancreas, including carcinoma, dysplasia, and hyperplasia.
abstract: KL-6 is known as a useful serum biomarker of the disease activity in interstitial pneumonias. We investigated its usefulness as a biomarker for subtyping intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. IPMNs are generally divided into 4 subtypes, namely pancreatobiliary (PB), intestinal (INT), gastric (GS), and oncocytic (ONC). Aside from the KL-6 antibody, the MUC1, MUC2, MUC5AC, MUC6, and MIB-1 antibodies were also examined. Eighteen IPMN cases were examined, including 12 cases of intraductal papillary mucinous carcinomas (IPMCs) simultaneously associated with dysplasia (IPMDs) and hyperplasia (IPMHs) and 6 IPMD cases with IPMH. KL-6 antibody was positive in the 8 IPMC cases, corresponding to a MUC2-negative PB subtype, but negative in 4 IPMC cases, corresponding to the INT subtype, which is positive for MUC2. IPMD of moderate-to-severe degree positively stained for the KL-6 antibody in the IPMC cases of the PB subtype but not in those of the INT subtype. The IPMH cases were mostly negative for KL-6, similar to the mild IPMD cases. In the 6 cases of mild IPMD and/or IPMH, KL-6 and MUC2 expressions were mostly negative. In conclusion, the KL-6 antibody is immunohistochemically a good biomarker of the PB subtype of IPMC, but not the INT subtype. Identifying IPMN subtypes based on KL-6 stainability would be useful. Clinicopathological studies with more IPMC cases might be needed for further progress in this field of study.
authors.affiliation: Division of Pathology, Matsuyama-shimin Hospital, Matsuyama, Ehime, 790-0067, Japan, y.ohtsuki@matsuyama-shimin-hsp.or.jp.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ohtsuki
authors.forename: Ryohei
authors.initials: R
authors.lastname: Watanabe
authors.forename: Masashi
authors.initials: M
authors.lastname: Kimura
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Nomura
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Maeda
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kito
authors.forename: Miyuki
authors.initials: M
authors.lastname: Takeji
authors.forename: Gang-Hong
authors.initials: GH
authors.lastname: Lee
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Furihata
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000378:metabolism / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D000906:Antibodies; D015415:Biomarkers; C060192:MUC1 protein, human; D018396:Mucin-1