title: Non-cystic solid-pseudopapillary tumor of the pancreas showing nuclear accumulation and activating gene mutation of beta-catenin.
abstract: Solid-pseudopapillary tumor (SPT) is an unusual pancreatic neoplasm that is characterized by a mixture of solid and cystic components and a fibrous capsule. Recently, the tumorigenesis of SPT has been reported to be associated with gene mutations of beta-catenin, which is a molecule participating in the Wnt signaling pathway. Reported herein is the case of a 53-year-old woman with SPT. The tumor, approximately 3 cm in diameter in the pancreas body, had a clear margin and central calcification but had neither a cystic component nor fibrous capsule. Several lines of pathological findings in the surgically resected specimen indicated SPT: (i) pseudopapillary proliferation of eosinophilic polygonal cells with oval nuclei; (ii) positive expression of several marker molecules indicating differentiation into acinar and endocrine cells; and (iii) zymogen granule-like structures in the cytoplasm on electron microscopy. Further, the tumor cells had intense nuclear accumulation of beta-catenin and an activating mutation, (34)Gly(GGA) to Arg(AGA), in exon 3 of the beta-catenin gene, as previously reported in most SPT. These findings suggest that association of the beta-catenin phenotype with development of the rare phenotype of SPT, a non-cystic and unencapsulated tumor, is unlikely.
authors.affiliation: Department of Gastroenterology and Hepatology, Kochi Medical School, Nankoku, Kochi, Japan. nisao@med.kochi-u.ac.jp
authors.forename: Isao
authors.initials: I
authors.lastname: Nishimori
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Kohsaki
authors.forename: Naoshige
authors.initials: N
authors.lastname: Tochika
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Minakuchi
authors.forename: Takehiro
authors.initials: T
authors.lastname: Okabayashi
authors.forename: Michiya
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hanazaki
authors.forename: Saburo
authors.initials: S
authors.lastname: Onishi
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D002467:Cell Nucleus / Q000473:pathology*; D018292:Cystadenoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D004252:DNA Mutational Analysis; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D009154:Mutation; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D022142:Secretory Vesicles / Q000648:ultrastructure; D017422:Sequence Analysis, DNA; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D051176:beta Catenin