散发神经鞘瘤22号染色体杂合子丢失

目的分析神经鞘瘤22号染色体(CHR22)杂合子丢失及其与临床行为之间的关系.方法选择4个具有高度多态性的微卫星标记物,通过变性聚丙烯酰胺凝胶、银染观察36例神经鞘瘤CHR22杂合子丢失(LOH)频率;以免疫组织化学方法检测Ki-67、PCNA的增殖指数.结果 36例神经鞘瘤中15例发生CHR22 杂合子丢失(41.6%),4个微卫星标记物缺失的频率分别为19.4%(D22S268)、22.2%(D22S264)、19.4%(D22S280)、 16.7%(CRYB2);发生CHR22缺失的神经鞘瘤的增殖指数高于无缺失者(P<0.05).结论 CHR22 杂合子丢失是神经鞘瘤发生中的常发事件,缺失的区域包括NF2基因,CHR22 杂合子丢失与听神经瘤的临床行为有一定的关系,CHR22 杂合子丢失可能是神经鞘瘤增殖的重要因素.     

散发神经鞘瘤22号染色体杂合子丢失发生的研究

目的探讨散发神经鞘瘤病人22号染色体（CHR22）杂合子丢失（LOH）情况及其与肿瘤增殖的关系。方法选取4个与NF2基因密切相关的多态性微卫星标记物,应用PCR方法研究54例神经鞘瘤的LOH情况。采用Ki-67和增殖细胞核抗原（PCNA）评估增殖指数。结果23例（42.6%）CHR22发生LOH,听神经鞘瘤发生率显著性高于脊神经鞘瘤（χ2=5.14,P〈0.05）。发生LOH者增殖指数明显高于无LOH者（Pki-67=0.0079,PPCNA=0.0021）。结论在散发神经鞘瘤中,CHR22LOH是常发事件;听神经瘤与脊神经鞘瘤LOH发生率有显著性差异,CHR22LOH与神经鞘瘤的增殖活动性有关。     

神经鞘瘤的NF2基因2、4、6、13外显子突变分析

目的分析神经鞘瘤NF2基因2、4、6、13外显子的突变.方法应用PCR-SSCP、DNA测序观察36例神经鞘瘤中发生的NF2基因突变,用PCNA免疫组织化学方法分析听神经瘤的增殖指数.结果36例神经鞘瘤中有13个突变,包括缺失、插入所致的移码突变6例,2例无义突变,2例反义突变,3例剪接位点改变;其中发生于E2的4例、E4的2例、E6的4例、E13的2例;发生突变的听神经瘤生长指数、增殖指数亦较高(P＜0.05).结论NF2基因突变是神经鞘瘤发生中的常发事件,是影响听神经瘤临床生物行为的重要因素.     

神经鞘瘤的NF2基因突变分析

目的 分析散发神经鞘瘤发生NF2基因突变及其与临床行为之间的关系。方法 应用PCR－SSCP、DNA测序观察36例神经鞘瘤中发生的NF2基因突变，用Ki-67、PCNA免疫组织化学分析听神经瘤的增殖指数。结果 36例神经鞘瘤中有13个突变，包括缺失、插入所致的移码突变6例，2例无突变，2例反义突变，3例剪接位点改变；其中发生于E2的4例、E4的2例、E6的4例、E13的2例；发生突变的听神经瘤生长指数、增殖指数亦较高。结论 NF2基因突变是神经鞘瘤发生中的常发事件，其与肿瘤的临床行为之间有一定的关系。     

人脑肿瘤染色体位点特异性杂合性丢失的研究

目的通过检测脑肿瘤杂合性丢失(LOH)的集中区域协助有关肿瘤抑制基因(TSG)的查找。方法选取9个微卫星多态标记,以PCR扩增-变性测序凝胶电泳检测67对瘤标本和相应正常组织DNA。结果胶质瘤在13q、19q和22q等位点存在较高频率(>20％)的LOH,脑膜瘤在22q和1p出现高频率(>30％)的LOH,神经鞘瘤仅在22q位点出现40％的LOH。结论脑肿瘤高频率的染色体位点特异性LOH与TSGs的失活密切相关。     

神经鞘瘤中NF2基因外显子2突变及意义

目的 :研究神经鞘瘤中 型多发神经纤维瘤病基因 (NF2 )外显子 2的突变及其意义。方法 :用 PCR- SS-CP、 DNA测序检测 36例神经鞘瘤 (听神经瘤 16例 ,其它 2 0例 )中 NF2基因外显子 2的突变。结果 :我们共发现 4例突变 ,均为听神经瘤 ,其中移码突变 2例、反义突变 2例。结论 :NF2基因外显子 2的突变可能是听神经瘤发生中的关键因素。     

原发性腹膜后神经鞘瘤的诊断与显微外科手术治疗

目的探讨原发性腹膜后神经鞘瘤的诊断和显微外科手术治疗的优缺点。方法对22例原发性腹膜后神经鞘瘤患者的诊断和显微外科手术切除的资料进行回顾性分析。结果 22例患者中肿瘤全切17例(77.3%),次全切5例(22.7%);无严重手术并发症;出血量少,平均每例220 ml。结论原发性腹膜后神经鞘瘤早期诊断困难,术前确切病理诊断依赖肿瘤穿刺活检;显微外科手术切除是一种安全有效的手术方式。     

颈椎髓内神经鞘瘤1例并文献复习

正神经鞘瘤(Schwannomas)是椎管内最常见的良性肿瘤,多位于髓外硬膜下或硬膜外。髓内神经鞘瘤(Intramedullary Schwannomas)是罕见的椎管内肿瘤,仅仅占神经鞘瘤的1.1%~[1],占髓内原发肿瘤的0.3%~1.5%~[2]。现报告1例高颈段髓内神经鞘瘤,并通过结合近几年国内外文献复习对髓内神经鞘瘤的诊治分析如下。1病例患者男性,46岁,因"右下肢酸痛1年,加重伴左上肢乏     

桥小脑角肿瘤致三叉神经痛45例分析

1984～1992年作者治疗三叉神经痛456例,其中病因为脑瘤者45例(9.9％)。胆脂瘤22例,脑膜瘤18例,神经鞘瘤5例。平均发病年龄分别为48.0、58.2、44.4岁。而单纯因血管压迫神经致三叉神经痛(NVC)者平均发病年龄61.0岁。胆脂瘤与神经鞘瘤患者与NVC比年龄显著低(P<0.01)。痛疼分布范围与NVC组相同,第Ⅱ、Ⅲ枝41例(91.1％),第Ⅰ枝4例(8.9％)。痛疼性质与NVC者相同,均以发作性痛疼为主。除三叉神经痛外,大多无其他异常神经症状,无面部知觉减退,角膜反射保留。但肿瘤直径大于4cm的2例患者出现面部感觉减退,外展神经及听神经损害等症状。有1例三叉神经鞘瘤和3例听神经瘤患者伴该神经的损害症状。     

颅内非听神经性神经鞘瘤的放射外科治疗临床研究

目的 回顾性分析伽玛刀放射外科对非听神经性神经鞘瘤的疗效及治疗剂量.方法 应用γ刀治疗非听神经神经鞘瘤,43例获得完全随访资料,包括24例三叉神经鞘瘤和19例颈静脉孔神经鞘瘤.以50%～80%等剂量曲线包绕靶区,肿瘤中位剂量分别为13 Gy(三叉神经鞘瘤)和15 Gy(颈静脉孔神经鞘瘤).结果 43例患者平均随访时间62个月.本组随访影像提示24例三叉神经鞘瘤患者伽玛刀治疗后肿瘤基本消失的4例(16.6%),肿瘤体积明显萎缩的12例(50.0%),肿瘤体积没有明显改变的6例(25%),肿瘤体积增大的2例(8.3%),肿瘤总控制率91.7%(22/24).19例颈神经孔神经鞘瘤患者伽玛刀治疗后肿瘤基本消失的3例(15.8%),肿瘤体积明显萎缩的9例(47.4%),肿瘤体积没有明显改变的6例(31.6%),肿瘤体积增大的1例(5.3%),肿瘤总控制率94.7%.本组患者肿瘤局部控制率为93%(41/44).临床症状改善总有效率为88.4%(38/43).结论 γ刀放射外科对非听神经性神经鞘瘤有良好的中长期控制作用,毒副作用较少.     

Expression of Ki-67 antigen and vascular endothelial growth factor in sporadic and neurofibromatosis type 2-associated schwannomas

Neurofibromatosis type 2 (NF2) is a formidable disease with considerable morbidity. Among tumors associated with NF2, schwannomas are the most difficult to treat because they are multiple and tend to recur. Vascular endothelial growth factor (VEGF) has been reported to act as a survival factor for Schwann cells. We, therefore, investigated VEGF expression in NF2-associated and sporadic schwannomas. We also evaluated the proliferative potential of these tumors by Ki-67 staining (MIB-1 labeling index) and microvascular density by CD34 staining. Immunohistochemistry was performed in 8 schwannomas from 6 NF2 patients, 2 schwannomas from 2 probable NF2 patients and 10 sporadic schwannomas. VEGF immunostaining was present in most schwannomas: all sporadic schwannomas and 8 of 10 schwannomas from NF2 or probable NF2 patients (NF2 group). No difference was evident in VEGF staining between the 2 groups. MIB-1 labeling index was significantly higher in the NF2 group (3.8 +/- 1.7) than the sporadic group (2.0 +/- 1.0, p < 0.01). Microvascular density was higher in the NF2 group (12.9 +/- 6.0) than the sporadic group (9.4 +/- 3.5), but not significantly (p = 0.06). Although VEGF alone cannot explain the higher proliferative potential in NF2-associated schwannomas, VEGF could be a factor influencing the proliferative potential of schwannomas.     

Laryngeal plexiform schwannoma as first symptom in a patient with neurofibromatosis type 2

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by bilateral vestibular schwannomas. The initial symptoms of NF2 are usually hearing loss and tinnitus caused by vestibular schwannomas. Although other intracranial, spinal, or skin tumors also occur in NF2, laryngeal lesions are very rare. We report a rare case of NF2 with laryngeal plexiform schwannoma as first symptom. A 38-year-old man presented with a smooth-surfaced submucosal supraglottic mass. Two round masses in the left chest wall and left supraclavicular fossa were noted incidentally during investigation of the laryngeal mass. Magnetic resonance imaging (MRI) findings for these masses were identical to those of the laryngeal mass. No typical symptoms related to NF2 were identified. Histologically, the laryngeal tumor represented plexiform schwannoma. We thus considered that the two round masses in the left chest wall and left supraclavicular fossa might also represent plexiform schwannomas. NF2 was suspected, as a high incidence of multiple plexiform schwannomas has been suggested for patients with NF2. MRI of brain lesions demonstrated bilateral vestibular schwannomas and multiple meningiomas. Finally, NF2 with laryngeal plexiform schwannoma was diagnosed. Recognizing that multiple plexiform schwannomas could be associated with NF2 is important.     

Allelic losses in neurofibromatosis 2-associated meningiomas

More than 50% of patients with neurofibromatosis 2 (NF2) develop meningiomas. Recently, a higher proliferative activity, more mitotic figures, and greater nuclear pleomorphism have been described for NF2-associated meningiomas compared with sporadic ones. To analyze whether such histological differences could reflect underlying genetic differences, we examined 30 meningiomas from 22 NF2 patients for allelic losses on those chromosome arms that are frequently affected by deletions in sporadic meningiomas. In addition, we assessed the proliferative activity of the tumors and studied NF2 germline mutations. Twenty-three meningiomas corresponded to WHO grade I (10 fibrous, 6 psammomatous, 4 transitional, 3 meningothelial) and 7 to WHO grade II. The average MIB-1 index was 1.60 +/- 0.85 (WHO grade I: 1.41 +/- 0.80, WHO grade II: 2.13 +/- 0.82). When compared with several published studies of sporadic meningiomas, the MIB-1 index in NF2-associated meningiomas was not higher. Loss of heterozygosity (LOH) flanking or within the NF2 locus at 22q12 was detected in 100% of the tumors. LOH on 1p was the second most frequent abnormality (40%), followed by losses on 10q (27%), 6q and 14q (24%), 18q (23%), and 9p (17%). LOH on 19q and 17p, which is not commonly seen in sporadic meningiomas, was also only rarely detected in NF2-associated meningiomas. NF2 gene mutations were detected in 8 of 15 patients analyzed and were located in exons 2, 5, 6, 7, and 8. We conclude that sporadic and NF2-associated meningiomas share a common spectrum and frequency of allelic deletions as well as, in contrast to previous observations, a similar proliferative activity.     

Pediatric acoustic schwannoma showing rapid regrowth with high proliferative activity

Acoustic schwannoma is a slow-growing tumor and usually occurs in adult patients. We report a rare pediatric case of acoustic schwannoma with high proliferative potential. A 10-year-old boy was diagnosed as having a right cerebellopontine angle tumor. The tumor was subtotally resected. Histological examination revealed a typical acoustic schwannoma with a few mitotic figures. Chromosomal analysis showed no abnormality on the long arm of chromosome 22 associated with neurofibromatosis type 2. The lesion regrew rapidly as an acoustic schwannoma, necessitating subtotal resection on three occasions and CyberKnife radiosurgery. The immunohistochemical MIB-1 staining indices of the specimens obtained at the first, second, and third operations were 2.3%, 4.6% and 14.7%, respectively. The immunohistochemical proliferative potential of acoustic schwannoma is discussed. Received: 6 February 1999 Revised: 8 April 1999     

Intracranial intraparenchymal and intraventricular schwannomas: Report of 18 cases

Objective

Intracranial schwannomas of the brain, which are unrelated to the cranial nerves, are extremely rare. In this article, we present a series of eighteen cases of intracranial intraparenchymal and intraventricular schwannomas, which is the largest series to date.

Methods

During the 10-year period from January 2000 to October 2010, we encountered 2491 histologically established cases of intracranial schwannomas, of which only 18 were not related to the cranial nerves. Clinical profiles, radiological features, surgical procedures, intraoperative findings and outcomes were extracted from the patient records and neuroimaging data.

Results

No patients were preoperatively diagnosed with schwannoma. The diagnosis of schwannoma was made by pathological examination with H&E staining and immunohistochemical examination. The 18 cases with intracranial ectopic schwannomas account for 0.8% of all the intracranial schwannomas that were observed within the same time period at our hospital. The age distribution of the patients ranged from 7 to 78 years. There was a slight male predominance: 11 male and 7 female patients (M:F = 1.6:1). Headaches were the most common presenting symptom and were found in most cases. Common neuroradiological characteristics included peritumoral edema and intralesional cysts.

Conclusion

Intracranial intraparenchymal and intraventricular schwannomas are rare, benign neoplasms that cannot be preoperatively differentiated from other parenchymal tumors. Surgical excision is curative, and the long-term prognosis is good. Additional studies are needed to confirm the histogenesis of this schwannoma type.