| Meningiomas are the most common primary human intracranial tumors that arise from meningothelial cells found in the arachnoid villi of the meninges,the membrances covering the brain and spinal cord, meningiomas are primarily benign tumors that may be cured by excision, although some are inoperable or invasive and are not amenable to surgical removal. Because histological features are not always reliable tools in assessing the aggressiveness of meningioma behaviour, many investigators have used the extent of surgical resection and the the rate of tumour regrowth to predict recurrence. Although various histopathologic features have been associated with aggressive behavior or recurrence of meningiomas, there is little agreement about which features are the most important and in what combination. The objective of this study was to formulate diagnostic criteria for atypical meningioma. The tumour cell proliferation rate becames a particularly important issue since a certain number of viable tumour cells may remain after macroscopical total excision. Efforts have also been focused on other fastors of prognostic significance. Numerous studies have been performed that there is a complexnetwork of cytokine interaction present in human meningiomas and that this network is important in the growth of these tumors, Such as VEGF, PDGF> FGF^ IGF, TGF, EGF .Numerous studies have been performed that examined the role of the TGF-a in meningiomas and the correlation of receptor presence with the clinicopathological features of meningiomasare unclear. Further investigations into TGF-a should increase our understanding of the biology of meningiomas. In this study, we examined immunohistochemical expression of TGF-a in 57cases of meningiomas.Materials and Methods:Fifty-seven patients with primary meningiomas, operated on in the department of Neurosurgery at the ZHEJING university second affiliated hospital from Jan. 2000 to December. 2001, were selected from the Department of Pathology files. Among them, 17 cases weremen and 40 were women , aged from 29 to 74 years with a mean age of 52 years. According to the criteria of WHO(1993), all cases were reviewed and eval uated for tumor grade and histological subtype. There were 45 benign, 5 atypical and 7 malignant meningiomas .The 4 urn tumor sections were used for immunohistochemical staining for TGF-a and Ki-67. Paraffin -embedded tissue sections of the meningiomas were stained with antibodies against TGF-a and Ki-67 using Envision System immunohistochemical technique. Those cell nuclers whose colors were stained to be brown-yellow were identified to be Ki-67 positive cells. Those cell cytoplasm whose colors were stained to be brown-yellow wereidentified to be TGF-a positive cells. Cell counting was performed at high power (400 ) . Depending on the size of the tumour section , a total of 1000-3000 tumour nuclei were counted from 4 to 10 microscope fields containing the highest density of labeled tumour nuclei. The MIB LI was expressed as a percentage of MIB-1-positive tumour nuclei per total tumour nuclei counted per specimen. Counts were made without paying attention to the tumour grade or knowledge of patient outcome. Nuclei of vascular endothelial cells were excluded from counts. Cytoplasmic TGF-a staining was scored as follows:0(no staining), 1(< 10%), 2(10-30%), 3(30-50%), 4(50-80%), and 5(>80% of estimated tumour area stained). The immunohistochemical staining kit for TGF- a and Ki-6 were purchased from Wuhan Boster Biotechnilogical company. The experiment was performed according to the instructional manual of the kit. Large intestine cancer tissue section and antiades tissue section were provided by Wuhan Boster Biotechnological company and used as positive control for TGF-a and Ki-6, respectively. PBS, instead of the first antibody, was used as a negative control.AnalysisSPSS10. 0 statistical computer programs were used, if P<0. 05, it means that difference between two groups is significant.Results1 Immunoreactivity of TGF-a in meningiomas In most...
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