No abstract availble.
DNA Mutational Analysis ; Humans ; *Microsatellite Instability ; Neoplasm Staging ; Prognosis ; Stomach Neoplasms/*diagnosis/genetics/surgery

BACKGROUND/AIMS: Microsatellite instability (MSI) is defined as a change of any length due to either insertion or deletion of repeating units, in a microsatellite within a tumor when compared to normal tissue. MSI is closely related with genetic instability, particularly in hereditary nonpolyposis colorectal cancer. MSI is found in 10-50% of all gastric cancers, suggesting that MSI may play an important role in carcinogenesis. The aim of this study was to investigate the relationship between microsatellite instability and clinicopathologic features in early gastric cancers (EGCs) treated by endoscopic submucosal dissection (ESD). METHODS: We analyzed clinicopathological features of 95 specimens of EGCs including MSI, histologic type, mucin phenotype, p53, VEGF, location of cancer, depth of invasion, incidence of synchronous and metachronous cancer, age, and gender derived from 94 patients, treated by ESD during recent 19 months were analyzed in this study. RESULTS: According to microsatellite stability, MSI was observed in 13 (13.7%) cases of 95 specimens. The incidence of MSI was increased in patients with cancer at lower part of stomach and female gender. There was no significant relation between MSI and clinicopathologic features including histologic type, mucin phenotype, p53, VEGF, and depth of invasion. CONCLUSIONS: Our results demonstrate that there is no relationship between MSI and clinicopathologic features except tumor location and gender in ECGs treated by ESD. However, further studies are needed to evaluate the significance of MSI in EGCs.
Adult ; Aged ; Aged, 80 and over ; DNA Mutational Analysis ; Data Interpretation, Statistical ; Endoscopy, Gastrointestinal ; Female ; Humans ; Male ; *Microsatellite Instability ; Middle Aged ; Mucins/analysis ; Neoplasm Staging ; Predictive Value of Tests ; Stomach Neoplasms/*diagnosis/genetics/surgery ; Tumor Suppressor Protein p53/analysis ; Vascular Endothelial Growth Factor A/analysis

OBJECTIVETo study the clinical and pathologic features of gastric schwannomas.

METHODSThe 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.

RESULTSThe 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.

CONCLUSIONSGastric 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.

Adult ; Aged ; Aged, 80 and over ; Diagnosis, Differential ; Exons ; Female ; Follow-Up Studies ; Gastrectomy ; methods ; Gastrointestinal Stromal Tumors ; metabolism ; pathology ; Glial Fibrillary Acidic Protein ; metabolism ; Humans ; Intermediate Filament Proteins ; metabolism ; Leiomyoma ; metabolism ; pathology ; Leiomyosarcoma ; metabolism ; pathology ; Male ; Middle Aged ; Mutation ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurilemmoma ; metabolism ; pathology ; surgery ; Neurofibroma ; metabolism ; pathology ; Receptor, Platelet-Derived Growth Factor alpha ; genetics ; metabolism ; S100 Proteins ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism