血管外膜细胞瘤p53和Ki-67的表达与肿瘤分级和复发的关系

目的 探讨中枢神经系统血管外膜细胞瘤(HPC)中p53及Ki-67的表达与肿瘤的分级和复发的关系. 方法 回顾性分析北京天坛医院自2005年1月采用至2008年1月手术切除治疗的97例中枢神经系统HPC患者的临床资料,HE染色97例FIPC标本并按照WHO标准进行分级;免疫组织化学染色检测并比较不同分级、复发和未复发肿瘤标本中p53和Ki-67的表达.结果 HE染色检测显示HPC分级Ⅱ级74例,Ⅲ级23例;随访结果显示未复发HPC 49例,复发39例;免疫组化检测结果显示Ⅱ级HPC中p53和Ki-67阳性细胞数均明显低于Ⅲ级,未复发病例的Ki-67和p53阳性细胞数均明显低于复发病例,差异均有统计学意义(P<0.05).结论 Ki-67、p53的表达越高,HPC的组织分级越高,复发风险越高,可作为判断HPC患者预后的指标.     

单中心107例脑膜瘤临床病理分析

目的探讨脑膜瘤WHO分级与预后的相关性以及免疫组化相关指标在各级中的表达。方法回顾性分析2013年03月～2018年12月间我院手术治疗的107例脑膜瘤患者的病理及预后资料,参照第4版WHO神经肿瘤分类标准将其分级,分析病理分级和复发的关系。采用组织化学及免疫组织化学染色测定波形蛋白(Vimentin)、上皮膜抗原(EMA)、S-100、细胞角蛋白(AE1/AE3)、GFAP以及Ki-67指数在肿瘤中的表达。结果WHOⅠ级99例,Ⅱ级5例,Ⅲ级3例,包括11种亚型。Ⅰ级脑膜瘤无进展生存时间(PFS)明显高于Ⅱ、Ⅲ级(P均0.05),Ⅱ、Ⅲ级脑膜瘤PFS无显著差异(P0.05)。Vimentin阳性107例,EMA阳性103例,S-100阳性13例,AE1/AE3阳性25例,GFAP均为阴性,上述各项指标在WHO分级中无显著差异(P均0.05)。Ki-67指数随肿瘤级别增高而增高(P0.01)。结论 WHO分级与脑膜瘤无进展生存时间密切相关,而Ki-67和肿瘤的良恶性相关,可作为鉴别良恶性脑膜瘤的重要分子标志物。     

30例非典型脑膜瘤患者临床病理特征与预后分析

目的 探讨非典型脑膜瘤(WHO grade Ⅱ)临床病理特征及其对生存期的影响.方法 收集2001年1月至2007年12月在中山大学肿瘤医院手术治疗并经病理确诊的、有完整临床随访资料的病例30例非典型脑膜瘤,应用Kaplan-Meier法、log-rank检验和Cox回归模型对其性别、年龄、肿瘤大小、Ki-67阳性率、P53阳性率、手术切除程度以及术后放疗等7项临床和病理特征进行单因素和多因素生存分析.结果 患者中位年龄47岁,其中男9例,女21例.中位随访时间62个月(22～110个月).平均复发时间为65个月(56～74个月),2年和5年无复发生存率分别为89%和62%.单因素和Cox多因素预后分析发现Ki-67表达和肿瘤大小两因素对生存期的影响有统计学意义(P＜0.05).结论 肿瘤体积大、Ki-67高表达的非典型脑膜瘤患者容易复发,术后要严密随访.     

多形性黄色星形细胞瘤的诊断与治疗(附22例分析)

目的探讨多形性黄色星形细胞瘤(PXA)的诊断及治疗。方法回顾性分析2008年10月至2016年12月手术治疗的22例PXA的临床资料。结果术中显微镜下和术后MRI复查证实肿瘤全切除16例,次全切除4例,部分切除2例。术后发生皮下积液3例、颅内感染2例、肺部感染1例,经对症治疗后痊愈。术后病理示,WHOⅡ级13例,Ⅲ级9例;免疫组化染色:胶质纤维酸性蛋白(+++),CD34(+++),Ki-67(灶状阳性),网状纤维(+)。19例术后随访1~8年,正常工作、生活10例,生活自理4例,生活需要照顾2例,死亡3例。复查MRI显示,肿瘤复发再次行手术7例;3例肿瘤呈多灶性复发,放弃进一步治疗死亡;其余9例随访期内未见明显肿瘤复发。结论 PXA多表现为良性肿瘤,少数病例有恶变的可能。MRI对PXA的诊断、手术以及术后预后判断具有积极意义,病理诊断是确诊的主要依据。肿瘤有残余、复发或间变型PXA,术后建议放、化疗,以改善预后。     

幕上星形细胞肿瘤Ki-67抗原表达及其预后作用

目的 探讨Ki-67抗原在幕上星形细胞肿瘤中的表达及其预后作用。方法 使用S-P免疫组化方法检测82例原发性幕上星形细胞肿瘤标本中Ki-67抗原的表达。单因素使用Kaplan-Meier法,多因素分析使用COX比例风险模型进行预后分析。结果Ki-67 指数在组织学分级GradeⅡ、Ⅲ、Ⅳ中分别为2.86%±1.57%,6.72%±3.95%,8.16%±3.92%(P<0.01)。单因素及多因素分析均提示Ki-67指数是独立的预后因素。在GradeⅡ中,Ki-67指数>2.5%与Grade Ⅲ中Ki-67指数≤2.5%的患者生存期差异无显著性(P>0.05);在GradeⅣ中,Ki-67指数≤2.5%与>2.5%的患者生存期有显著性差异(P<0.01)。结论 Ki-67指数随着各病理级别增高而增高;Ki-67指数>2.5%提示预后较差。在同一病理级别中,Ki-67指数不同,其预后有显著性差异。而部分不同病理级别的患者,随着Ki-67指数的不同,其生存期却无显著差异。联合组织病理检查及Ki-67指数检测有助于更精确地判断预后。     

自动免疫组织化学染色仪在胶质瘤病理诊断中的应用

目的探讨LeicaBOND-MAXTM全自动免疫组织化学染色仪标记的Ki-67抗原在胶质瘤组织病理学诊断中的意义。方法选择经神经外科手术切除并经病理明确诊断的胶质瘤组织标本共计120例(WHOⅠ～Ⅳ级各30例),分别采用全自动免疫组织化学染色仪和手工操作EnVision二步法进行组织病理学检测。结果不同WHO分级与不同染色方法之间存在交互作用,且两种染色方法检测胶质瘤细胞胞核Ki-67抗原标记指数差异具有统计学意义(均P=0.000)。两种染色方法对WHOⅠ级和Ⅱ级胶质瘤细胞胞核Ki-67抗原标记指数的检测差异无统计学意义(均P>0.05);但WHOⅠ、Ⅱ级与Ⅲ、Ⅳ级之间,以及WHOⅢ级与Ⅳ级之间及其同一病理级别之间比较,全自动免疫组织化学染色仪检测胶质瘤细胞胞核Ki-67抗原标记指数均高于手工染色法(均P<0.05)。结论全自动免疫组织化学染色仪新技术带来的标准化可为组织病理学诊断提供更为准确的依据,对于分析和判断胶质瘤分级和预后具有重要意义。     

Ki-67和拓扑异构酶Ⅱα在脑胶质瘤中的表达及意义

目的检测脑胶质瘤中Ki-67和拓扑异构酶Ⅱα（TopoⅡα）的表达情况,并分析其表达强度与肿瘤病理分级的关系。方法采用免疫组织化学方法检测43例脑胶质瘤中Ki-67和TopoⅡα的表达情况。结果随着肿瘤病理级别的提高,Ki-67和TopoⅡ-α标记指数均增加,低级别组（Ⅰ、Ⅱ级）与Ⅲ级、Ⅳ级肿瘤之间的差异具有显著性意义（P〈0.05）。Ki-67与TopoⅡα表达呈显著正相关。结论Ki-67和TopoⅡα较准确地反映脑胶质瘤的增殖潜能和恶性程度,对判断脑胶质瘤患者的预后具有重要参考价值。     

脑膜瘤瘤周水肿与肿瘤部位、病理分级和Ki-67的相关性研究

目的分析脑膜瘤瘤周水肿(PTBE)与肿瘤发生部位、病理分级及Ki-67的关系。方法回顾性分析712例脑膜瘤病人的临床资料,采用统计学分析评估不同条件下PTBE的发生和水肿严重程度差异。结果发生PTBE 358例(50.3%)。非颅底较颅底脑膜瘤PTBE的发生率高(χ~2=14.686,P0.01),且水肿程度更重(χ~2=16.812,P0.01)。WHOⅡ级较Ⅰ级脑膜瘤PTBE发生率高(χ~2=32.403,P0.01),WHOⅢ级较Ⅱ级PTBE发生率高(χ~2=21.356,P0.05);且不同病理分级的PTBE水肿程度有差异(χ~2=40.482,P0.01)。在WHOⅠ级脑膜瘤中,血管瘤型、微囊型、分泌型和富于淋巴-浆细胞型4种脑膜瘤总PTBE发生率较其他5种类型脑膜瘤高(χ~2=48.078,P0.01),且与WHOⅡ、Ⅲ级总PTBE发生率相当(χ~2=3.238,P0.05)。Ki-67在同级别病理类型中随着PTBE严重程度呈现升高趋势(χ~2=33.359,P0.01)。Logistic回归分析显示:病理分级、Ki-67表达与PTBE的严重程度成正相关(P0.01)。结论脑膜瘤PTBE的发生及严重程度可在一定程度上反映肿瘤的恶性程度和Ki-67的表达情况,为临床手术方案、围手术期治疗及术后辅助治疗等提供重要参考。     

ATRX、P53表达的相关性及联合多因素对胶质瘤预后的意义

目的 探讨脑胶质瘤患者中ATRX失表达与P53过表达的相关性,并分析二者与临床多因素在胶质瘤诊断及预后中的意义。方法 收集2014年1月—2020年12月徐州医科大学附属医院神经外科收治的术后病理诊断为胶质瘤的患者92例,其中包括星形细胞瘤(WHOⅡ、Ⅲ级)30例、少突胶质细胞瘤(WHOⅡ、Ⅲ级)50例、胶质母细胞瘤(WHOⅣ级)12例,并使用免疫组织化学染色法检测ATRX与P53表达情况,并统计不同年龄、性别与二者间的关系;χ²检验分析ATRX失表达、P53过表达与不同病理类型脑胶质瘤的关系且二者表达之间的关系用Spearman等级相关分析法检验;Kaplan-Meier生存曲线分析二者对胶质瘤患者预后的影响,其他临床因素纳入多因素Cox回归分析。结果 ATRX与P53表达与胶质瘤病理类型相关(P<0.05);相关性分析显示,胶质瘤中ATRX与P53表达呈负相关(r=-0.580,P<0.01);多因素分析表明,胶质瘤患者的年龄≥60岁、病理分级WHOⅢ-Ⅳ级、术前KPS评分<60分、术后无放化疗、肿瘤直径≥5 cm、肿瘤非全切、ATRX失表达...     

星形细胞起源肿瘤Claudin-1、Ki-67、CD34表达水平与细胞增殖和侵袭的关系

目的 研究脑星形细胞起源肿瘤中紧密连接蛋白-1(Claudin-1)、Ki-67、CD34的表达及其与星形细胞起源肿瘤的侵袭、增殖和分级的关系.方法 应用免疫组织化学方法检测50例星形细胞起源肿瘤非肿瘤区、交界区和肿瘤区Claudin-1、细胞增殖标记抗体Ki-67、CD34的表达情况,分析其与肿瘤临床病理特征的关系.结果 组织学Ⅰ、Ⅱ级星形细胞起源肿瘤肿瘤区Claudin-1表达率(70.59%)高于Ⅲ、Ⅳ级的星形细胞起源肿瘤(9.09%)(P=0.000);Ⅲ、Ⅳ级星形细胞起源肿瘤肿瘤区、交界区和非肿瘤区Ki-67标记指数高于Ⅰ、Ⅱ级(P均=0.000);Ⅲ、Ⅳ级星形细胞起源肿瘤肿瘤区和交界区的微血管密度(MVD)高于Ⅰ、Ⅱ级(P=0.003,0.000);肿瘤区的Ki-67(12.74±6.93)高于交界区(7.42±3.93)和非肿瘤区(3.22±1.57)(P=0.000);肿瘤区的MVD(27.48±8.26)高于交界区(10.72±3.93)和非肿瘤区(6.48±1.45)(P=0.000).结论 Claudin-1、Ki-67、CD34的表达与星形细胞起源肿瘤的分级、增殖和侵袭有关,可作为判断肿瘤恶性度的重要指标.     

Value of KI-67/MIB-1 labeling index and simpson grading system to predict the recurrence of who grade I intracranial meningiomas compared to who grade II

Simpson grading of resection has been used as a predictor of intracranial meningioma (IM) recurrence. Histopathological findings, like the Ki-67/MIB-1 labeling index, may be useful in the assessment risk of recurrence. Our objective was to analyze the predictive value of meningioma recurrence using both parameters. We retrospectively studied 322 consecutive patients with histopathological diagnosis of IM WHO grade I and 43 patients with IM WHO grade II in a 13-year period. Multivariate survival analysis was performed. In the WHO grade I IM group, recurrence was observed in 28 patients (8.69%). The Cox regression model for WHO grade I IM, provided a significative hazard ratio (HR) for Ki-67/MIB-1 index ≥3 (HR = 36.35, p < 0.001) and Simpson’s grading resection, grade II (HR = 2.03, p = 0.045), grade III (HR = 3.41, p = 0.034) and grade IV (HR = 19.75, p ≥ 0.001). In the WHO grade II IM group, recurrence was observed in 10 patients (23.25%). The Cox regression model for WHO grade II IM, provided a significative hazard ratio (HR) for Ki-67/MIB-1 index ≥3% (HR = 1.66, p < 0.001) and Simpson’s grading resection grade III (HR = 3.96, p = 0.027). The Kaplan–Meier survival curve showed a similar distribution of survival between WHO grade I IM with Ki-67/MIB-1 ≥3% and WHO grade II IM. In WHO grade I meningiomas, the Ki-67/MIB-1 index and Simpson grading were both independent predictors of recurrence. A similar management protocol should be advisable for WHO grade I with Ki-67/MIB-1 ≥3% and WHO grade II meningiomas.     

Grading of diffusely infiltrating astrocytomas by quantitative histopathology, cell proliferation and image cytometric DNA analysis. Comparison of 133 tumours in the context of the WHO 1979 and WHO 1993 grading schemes

The aim of the study was to evaluate the applicability of quantitative histopathology as an aid for grading diffusely infiltrating astrocytomas. Primary astrocytomas were analysed for parameters (mean nuclear size, mitosis count, area fraction of endothelial cells and tumour necrosis, area fraction of nuclei, and Ki-67 (MIB-1) labelling index), which are closely related to the World Health Organization (WHO) 1979 and WHO 1993 grading criteria. All estimates correlated with the WHO histopathological grade and patient outcome. According to the receiver-operating characteristics curve, the presence of tumour necrosis and mitosis count (cut-off at 3 mitoses/mm2 of neoplastic tissue) showed the best sensitivity and specificity in separating patients with different survival. The multivariate survival analyses confirmed this result. A decision-tree model was constructed based on these two variables: twig I with less than 3 mitoses/mm2, twig II with equal or more than 3 mitoses/mm2 but no necrosis, and twig III with tumour necrosis. This model was found to be more strongly associated with survival than the WHO 1979 or WHO 1993 grading schemes. Low-malignancy astrocytomas (WHO grade II or twig I tumours) could be further divided into two prognostic categories by the image cytometric DNA analysis. The results put an emphasis on astrocytoma grading on mitosis counts (grade II vs. III) and tumour necrosis (grade III vs. IV). To standardize the sampling for mitosis counting, it is suggested that a parallel Ki-67 immunostaining be used for the identification of the most proliferative areas.     

多形性黄色瘤型星形细胞瘤的诊治分析:附7例报道并文献复习

目的 探讨多形性黄色瘤型星形细胞瘤（PXA）的临床表现、影像学表现、病理特征、治疗及预后。方法 回顾性分析2011年7月至2019年7月手术治疗的7例PXA的临床资料,并复习相关文献。结果 7例均以癫痫发作起病;7例肿瘤均位于大脑浅表部位,MRI表现呈实性4例,呈囊实性3例;7例均在显微镜下全切,5例术后行适形放疗,2例间变型术后行同步放化疗;术后病理WHOⅡ级5例,Ⅲ级2例。术后随访6个月~8年,存活6例,术后2例复发,其中1例死亡。结论 PXA临床罕见,癫痫发作是最常见的症状,影像学表现具有一定特点,其病理学特征有别于其他星形细胞瘤,治疗上应手术全切,对术后有残余、复发或间变者可给予放、化疗。     

血管内皮生长因子、细胞周期相关核抗原Ki-67抗体和p53表达水平与脑膜瘤术后瘤周水肿的相关性研究

目的 探讨血管内皮生长因子(Vascular endothelial growth factor,VEGF)、细胞周期相关核抗原Ki-67抗体和p53的表达水平对脑膜瘤术后瘤周水肿(Pedtumoral brain edema,PTBE)的影响.方法 选取2007年1月-2016年7月于本院就诊的脑膜瘤手术患者159例...     

Gliomas of the optic nerve: histological, immunohistochemical (MIB-1 and p53), and MRI analysis

Gliomas of the optic nerve, although typically of pilocytic (WHO grade I) histology, can present within the spectrum of astrocytic neoplasia including glioblastoma (WHO grade IV). In certain cases, histologic features alone make the distinction between pilocytic and diffuse astrocytomas difficult. We reviewed 22 cases of optic nerve gliomas, 19 of which were pilocytic astrocytomas (PA), and 3 of which were diffuse, non-pilocytic astrocytomas. The cases were evaluated for their clinical course, radiographic appearance, histologic grade, and proliferation indices as detected by MIB-1 (Ki-67) and p53 antibodies. Of the 19 PA, 14 showed no tumor growth by magnetic resonance imaging, and had Ki-67 and p53 labeling indices (LI) of < 1%. The other 5 PA exhibited aggressive behavior manifest by marked diffuse infiltrative tumor growth causing death in 2 patients, 1 of whom was diagnosed with neurofibromatosis type 1 (immunoperoxidase and radiographs not available), and marked local growth with an average time to growth of 39.3 months, a Ki-67 LI of 2–3%, and a p53 LI of < 1% in three others. Three of the five aggressive PA histologically demonstrated a finely reticulated pattern, a pattern that appears as an exaggeration or expansion of the normal neuroglia of the optic nerve, and may simulate a diffuse low-grade astrocytoma. Two demonstrated the coarsely reticulated pattern, with the biphasic and microcystic pattern typical of PA. Three diffuse astrocytomas (2 anaplastic astrocytomas and 1 glioblastoma) originated clinically and radiographically from the optic nerve, and revealed a Ki-67 LI of 2–12%, a p53 LI of 2–8%, and an average time to growth of 8 months. We conclude that the majority of PA of the optic nerve are non-aggressive, stabilize radiographically, and have Ki-67 and p53 LI < 1%. However, a subpopulation of PA has a propensity for aggressive behavior, and are identified by a Ki-67 LI of 2–3% and a p53 LI of < 1%. Diffuse astrocytomas have both Ki-67 and p53 LI > 2%. Thus, in cases of aggressive optic nerve tumors in which the histologic review of biopsy material cannot confidently confirm the diagnosis of pilocytic or diffuse fibrillary glioma, a p53 LI of > 1% appears to favor the diagnosis of diffuse astrocytoma. Received: 18 May 1999 / Revised: 10 August 1999 / Accepted: 18 August 1999     

Outcome of resection of WHO Grade II meningioma and correlation of pathological and radiological predictive factors for recurrence

This study investigated whether extent of surgical resection (Simpson and Shinshu grade) along with pathological and radiological factors influence the tumor control and recurrence-free survival (RFS) of patients with World Health Organization (WHO) grade II meningiomas. The clinical, radiological and surgical notes on the 59 patients with WHO grade II meningioma managed at our institution over 20 years were retrospectively reviewed. In this study, median survival time was 41 months. The overall recurrence rate in Simpson grades I and II resection was 31%. In grades III and IV, the overall recurrence rate was 73%, and this high recurrence rate in these groups was confined within 5 years. In Cox regression analysis, combined data of grades (I and II)/complete resection showed a significant difference in RFS compared to grades (III and IV)/subtotal resection (p = 0.0001). A similar trend of RFS (p = 0.0001) was observed with the Shinshu grading system of resection. In addition, a Ki-67% marker for proliferation less than 15% (p = 0.029), absence of certain radiological features including heterogeneous enhancement, cyst formation and peritumoral edema (p = 0.006), and repeat surgery for recurrent meningioma was associated with better survival (p = 0.014). However, radiosurgery did not have a beneficial role in the treatment of recurrence of atypical meningioma. The Simpson grading system is the primary predictor of recurrence of WHO grade II meningioma after resection. In addition, certain pathological and radiological features need to be considered as possible factors of recurrence after resection. Lastly, depending on the likely risks and surgical morbidity, repeat surgical resection should be performed for recurrent atypical meningioma.     

Malignant progression in pleomorphic xanthoastrocytoma: personal experience and review of the literature

Pleomorphic xanthoastrocytoma (PXA) is a rare primary low-grade astrocytic tumor, recently classified as a neuroglial tumor. It generally occurs in children and young adults and shows benign behaviour (WHO II), although an anaplastic variant and malignant potential have been described. Pleomorphic xanthoastrocytomas with malignant transformation have been reported in three out of eight patients operated on for this type of tumor in our department in the last 15 years. The three patients were two adult women and a child, the primary tumors were located in the cortex of the right temporal lobe, and treatment consisted of complete surgical resection. Histological examination revealed simple PXA in two patients and a PXA with anaplastic foci in the other. Mean recurrence time was 5.7 years, with the original xanthoastrocytoma evolving to glioblastoma in two cases and anaplastic astrocytoma in the third. All three patients underwent a second operation, followed by adjuvant therapies. Two died from tumor progression and one from brain edema after intracerebral haemorrhage. A review of the available PXA literature dating back to 1979 revealed 16 cases of primary anaplastic astrocytoma and 21 cases of PXA with malignant transformation. Our experience adds three more cases of malignant transformations, outlining once again the potential malignancy of pleomorphic xanthoastrocytomas and the fact that prognosis in these cases is the same as for primary anaplastic astrocytoma and glioblastoma. Analysis of glioneuronal markers, Ki67 and p53 in all pleomorphic xanthoastrocytomas did not prove to be a discriminating factor to identify a subgroup of xanthoastrocytomas prone to malignancy. Accordingly, these tumors demand close long-term clinical and radiological follow-up.     

Prognostic Factors and Therapeutic Outcomes in 22 Patients with Pleomorphic Xanthoastrocytoma

Objective

Pleomorphic xanthoastrocytoma (PXA) is a rare primary low-grade astrocytic tumor classified as WHO II. It is generally benign, but disease progression and malignant transformation have been reported. Prognostic factors for PXA and optimal therapies are not well known.

Methods

The study period was January 2000 to March 2012. Data on MR findings, histology, surgical extents and adjuvant therapies were reviewed in twenty-two patients diagnosed with PXA.

Results

The frequent symptoms of PXA included seizures, headaches and neurologic deficits. Tumors were most common in the temporal lobe followed by frontal, parietal and occipital lobes. One patient who died from immediate post-operative complications was excluded from the statistical analysis. Of the remaining 21 patients, 3 (14%) died and 7 (33%) showed disease progression. Atypical tumor location (p<0.001), peritumoral edema (p=0.022) and large tumor size (p=0.048) were correlated with disease progression, however, Ki-67 index and necrosis were not statistically significant. Disease progression occurred in three (21%) of 14 patients who underwent GTR, compared with 4 (57%) of 7 patients who did not undergo GTR, however, it was not statistically significant. Ten patients received adjuvant radiotherapy and the tumors were controlled in 5 of these patients.

Conclusion

The prognosis for PXA is good; in our patients overall survival was 84%, and event-free survival was 59% at 3 years. Atypical tumor location, peritumoral edema and large tumor size are significantly correlated with disease progression. GTR may provide prolonged disease control, and adjuvant radiotherapy may be beneficial, but further study is needed.     

Correlation of chromosomes 1p and 19q status and expressions of O6-methylguanine DNA methyltransferase (MGMT), p53 and Ki-67 in diffuse gliomas of World Health Organization (WHO) grades II and III: a clinicopathological study

Aims: The objective of the present study was to verify the correlation of chromosomes 1p and 19q status and expressions of O⁶-methylguanine DNA methyltransferase (MGMT), p53 and Ki-67 in diffuse gliomas of World Health Organization grades II and III. Methods: A series of 146 diffuse gliomas, including 45 oligodendrogliomas, 42 oligoastrocytomas and 59 astrocytomas, were analysed by denaturing high-performance liquid chromatography for 1p and 19q status and by immunohistochemistry for MGMT, p53 and Ki-67 expression patterns. The molecular alterations were then correlated with clinicopathological characteristics and with each other. Results: Loss of heterozygosity (LOH) on 1p, combined LOH on 1p and 19q, low MGMT expression and high Ki-67 expression were associated with oligodendroglial tumours, whereas high p53 expression was associated with astrocytic and mixed tumours. LOH on 1p and low MGMT expression were associated with grade II oligodendroglial tumours, whereas high expressions of p53 and Ki-67 were associated with grade III oligodendroglial tumours. In addition, high Ki-67 expression was associated with grade III astrocytomas. LOH on 1p and LOH on 19q were associated with nontemporal oligodendroglial tumours. Nonrandom associations were found between LOH on 1p and LOH on 19q, MGMT expression and p53 expression, and MGMT expression and Ki-67 expression, whereas mutual exclusions were found between LOH on 1p and 19q and p53 expression, and LOH on 1p and Ki-67 expression. Conclusions: The present study revealed significant interrelationships of the investigated molecular alterations and clinicopathological characteristics in diffuse gliomas of World Health Organization grades II and III, which support a promising role of molecular markers in the diagnostic assessment of these neoplasms.