title: [Clinical and pathologic features of gastric schwannoma].
abstract: OBJECTIVE
  To study the clinical and pathologic features of gastric schwannomas.
  
  
  METHODS
  The macroscopic and microscopic features of 9 cases of gastric schwannoma were analyzed. Immunohistochemical study for S-100 protein, CD117, CD34, neurofilament, desmin, nestin, glial fibrillary acidic protein, platelet derived growth factor-alpha (PDGFR-α) and vimentin was carried out. Mutation analysis of c-kit gene (exon 9, 11, 13 and 17) and PDGFR-α gene (exon 12 and 18) in 1 case was examined by PCR amplification and direct sequencing.
  
  
  RESULTS
  The patients included 5 males and 4 females. The age of patients ranged from 42 to 81 years (median = 56.5 years). The size of the tumors ranged from 2 to 9 cm in greatest diameter. Follow-up data in 8 cases (from 1 month to 65 months) showed no evidence of recurrence or metastasis. Gross examination showed that gastric schwannomas were homogeneous, firm, yellow-white and bore no true fibrous capsule. Histologically, all cases were composed of fascicles of spindle cells associated with nuclear palisading, Verocay body formation and peripheral cuff of reactive lymphoid aggregates. Some of them showed degenerative changes including cyst formation, calcification, hemorrhage, necrosis and hyalinization. Immunohistochemical study showed that the tumor cells were strongly positive for S-100 protein and vimentin. There was various degree of staining for nestin (8/9) and glial fibrillary acidic protein (6/9). They were negative for CD117, CD34, neurofilament, desmin and smooth muscle actin. One case showed focal positivity for PDGFR-α (1/9), with no mutations found.
  
  
  CONCLUSIONS
  Gastric schwannomas share similar histologic features with conventional soft tissue schwannomas, in addition to the presence a reactive lymphoid cuff. The clinical, macroscopic, histologic and immunohistochemical features of gastric schwannomas were different from those of gastrointestinal stromal tumors and leiomyomas.
authors.affiliation: Department of Pathology, People's Liberation Army General Hospital, Beijing 100853, China.
authors.forename: Zhan-bo
authors.initials: ZB
authors.lastname: Wang
authors.forename: Huai-yin
authors.initials: HY
authors.lastname: Shi
authors.forename: Jing
authors.initials: J
authors.lastname: Yuan
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Li-xin
authors.initials: LX
authors.lastname: Wei
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005091:Exons; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy / Q000379:methods; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism / Q000473:pathology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007381:Intermediate Filament Proteins / Q000378:metabolism; D007889:Leiomyoma / Q000378:metabolism / Q000473:pathology; D007890:Leiomyosarcoma / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D009442:Neurilemmoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D009455:Neurofibroma / Q000378:metabolism / Q000473:pathology; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics / Q000378:metabolism; D009418:S100 Proteins / Q000378:metabolism; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014746:Vimentin / Q000378:metabolism
chemical_list: D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; D064231:Nestin; D009418:S100 Proteins; D014746:Vimentin; D020796:Receptor, Platelet-Derived Growth Factor alpha