Case Report
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World J Gastroenterol. Jun 7, 2013; 19(21): 3358-3363
Published online Jun 7, 2013. doi: 10.3748/wjg.v19.i21.3358
Synchronous pancreatic solid pseudopapillary neoplasm and intraductal papillary mucinous neoplasm
Kenichi Hirabayashi, Giuseppe Zamboni, Hiroyuki Ito, Masami Ogawa, Yoshiaki Kawaguchi, Tomohiro Yamashita, Toshio Nakagohri, Naoya Nakamura
Kenichi Hirabayashi, Naoya Nakamura, Department of Pathology, Tokai University School of Medicine, Isehara 259-1193, Japan
Kenichi Hirabayashi, Giuseppe Zamboni, Department of Pathology, Ospedale Sacro Cuore Don Calabria, 37024 Negrar Verona, Italy
Giuseppe Zamboni, Department of Pathology, University of Verona, 37134 Negrar Verona, Italy
Hiroyuki Ito, Masami Ogawa, Yoshiaki Kawaguchi, Department of Gastroenterology, Tokai University School of Medicine, Isehara 259-1193, Japan
Tomohiro Yamashita, Department of Radiology, Tokai University School of Medicine, Isehara 259-1193, Japan
Toshio Nakagohri, Department of Gastroenterological Surgery, Tokai University School of Medicine, Isehara 259-1193, Japan
Author contributions: Ito H, Ogawa M, Kawaguchi Y and Nakagohri T provided the clinical data; Yamashita T provided the imaging data; Zamboni G and Nakamura N organized and revised the manuscript; Hirabayashi K wrote the manuscript.
Correspondence to: Kenichi Hirabayashi, MD, PhD, Department of Pathology, Ospedale Sacro Cuore Don Calabria, Via don Sempreboni 5, 37024 Negrar Verona, Italy. khira@is.icc.u-tokai.ac.jp
Telephone: +39-45-6013415 Fax: +39-45-7500480
Received: January 15, 2013
Revised: March 1, 2013
Accepted: March 15, 2013
Published online: June 7, 2013
Processing time: 139 Days and 19.3 Hours
Abstract

Solid pseudopapillary neoplasm (SPN) is a rare and low-grade malignant pancreatic neoplasm composed of poorly cohesive monomorphic neoplastic cells forming solid and pseudopapillary structures with frequent hemorrhagic-cystic degeneration. Intraductal papillary mucinous neoplasm (IPMN) is a pancreatic exocrine tumor composed of intraductal papillary growth of mucin containing neoplastic cells in the main pancreatic duct or its major branches. In the case presented here, a 53-year-old, Japanese man was found to have multiple cystic lesions and dilatation of the main pancreatic duct in the neck of the pancreas. Histological examination revealed a main-duct and branch-duct type IPMN, of the gastric-type, involving the neck of the pancreas, associated with a 0.5 cm SPN in the caudal side of the IPMN. We diagnosed this case as synchronous SPN and IPMN. As far as we know, only one other case of synchronous SPN and IPMN has been reported. Both the present case and the previously reported case showed abnormal nuclear expression of β-catenin in SPN, whereas IPMN showed no abnormal nuclear expression. These results suggest that β-catenin abnormality is not a common pathogenetic factor of synchronous SPN and IPMN.

Keywords: Intraductal papillary mucinous neoplasms; Solid pseudopapillary neoplasms; Pancreatic neoplasms; Synchronous neoplasms; Pancreas; Beta-catenin

Core tip: We report the second case of synchronous solid pseudopapillary neoplasm (SPN) and intraductal papillary mucinous neoplasm (IPMN) of the pancreas in a 53-year-old Japanese man. IPMN was classified as a “combined” type due to the involvement of both the main and branch ducts, and it showed a gastric subtype with low-grade dysplasia. Adjacent to the caudal side of IPMN, a 0.5-cm solid SPN was present. The SPN showed abnormal nuclear expression of β-catenin in SPN, whereas IPMN showed no abnormal nuclear expression. This result suggested that β-catenin abnormality is not a common pathogenetic factor of synchronous SPN or IPMN.