title: Intraductal tubulopapillary neoplasm of the pancreas with somatic BRAF mutation.
abstract: Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic tumor belonging to a newly recognized entity that is coined in the 2010 WHO classification. We present a case of ITPN-associated microinvasive adenocarcinoma that developed in an asymptomatic 78-year-old patient. The tumor demonstrated all the clinical, radiological, and pathological characteristics of ITPN, but it differs from other reported cases of ITPN in molecular analysis, which revealed a somatic mutation in BRAF (c.1799T>A; p.V600E) but no mutation in PIK3CA. Post-operative recurrence was discovered 34 months after tumor resection with negative margins and a 6-month course of adjuvant chemotherapy. To the best of our knowledge, this is the first case of ITPN with BRAF mutation. This case suggests that an activation of RAS-mitogen-activated protein kinase signaling pathway may play a role in development of some of ITPNs. A possible mechanism of tumor recurrence in ITPN is also discussed. Further case series with molecular study are awaited to delineate the clinicopathological and molecular characteristics of ITPN.
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan. tagatame0126@yahoo.co.jp.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Urata
authors.affiliation: Department of Pathology, Kurume University School of Medicine, Kurume, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Department of Pathology, Japanese Red Cross Kumamoto Hospital, Kumamoto, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Nagamine
authors.affiliation: Department of Gastroenterology, Tamana Regional Health Medical Center, Kumamoto, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Izumi
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Ginga
authors.initials: G
authors.lastname: Tonaki
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Iwasaki
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Sasaki
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamasaki
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Minami
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Rituko
authors.initials: R
authors.lastname: Yoshioka
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kitada
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Yoshi
authors.initials: Y
authors.lastname: Takekuma
authors.affiliation: Department of Surgery, Japanese Red Cross Kumamoto Hospital, Kumamoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yokomizo
authors.affiliation: Department of Pathology, Japanese Red Cross Kumamoto Hospital, Kumamoto, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Fukuda
authors.affiliation: Department of Pathology, Saitama International Medical Center, Saitama Medical University, Hidaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamaguchi
authors.affiliation: Institute for Integrated Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kuboki
authors.affiliation: Institute for Integrated Medical Sciences, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Furukawa
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Kumamoto Hospital, 2-1-1, Nagamine Minami, Kumamoto, Kumamoto, 861-8520, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Hifumi
keywords: BRAF; Intraductal tubulopapillary neoplasm; Microinvasion; Pancreas; Recurrence