title: Gastric schwannoma with adjacent external progression harbored aberrant NF2 gene.
abstract: Gastric schwannomas are rare benign mesenchymal tumors. We describe a schwannoma of gastric origin with adjacent external progression. Sections showed a spindle cell tumor arranged in interlaced bundles and fascicles that was S-100 and CD34 positive but c-KIT protein negative. Histology and immunohistochemistry revealed the typical appearance of a gastric schwannoma. Genetic evaluation revealed that the tumor harbored a point mutation in exon 6 of the tumor suppressor neurofibromatosis 2 (NF2) gene, which resulted in an amino acid substitution of NF2 protein, and no mutation in exon 4b of the NF1 gene. In conclusion, we identified a rare mutation of the NF2 gene in gastric schwannoma. A diagnosis can only be definitive when based on histological and immunohistochemical findings. Digestive tract schwannomas are rare mesenchymal tumors that are differentiated from gastrointestinal stromal tumors by the absence of KIT protein. Follow up suggested that complete resection is an effective long-term treatment strategy.
authors.affiliation: Department of Gastroenterology, Nagoya City University Graduate School of Medical Science, Mizuho-ku, Nagoya, Japan.
authors.forename: Naotaka
authors.initials: N
authors.lastname: Ogasawara
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ishiguro
authors.forename: Yukimi
authors.initials: Y
authors.lastname: Itoh
authors.forename: Syunsuke
authors.initials: S
authors.lastname: Nojiri
authors.forename: Eiji
authors.initials: E
authors.lastname: Kubota
authors.forename: Tsuneya
authors.initials: T
authors.lastname: Wada
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kataoka
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kuwabara
authors.forename: Takashi
authors.initials: T
authors.lastname: Joh
mesh_terms: D018450:Disease Progression; D005260:Female; D006801:Humans; D008875:Middle Aged; D009442:Neurilemmoma / Q000235:genetics* / Q000601:surgery; D016518:Neurofibromatosis 2 / Q000235:genetics*; D013274:Stomach Neoplasms / Q000235:genetics* / Q000601:surgery