Pytel Peter, Lukas Rimas V
Department of Pathology, University of Chicago Medical Center, Chicago, Illinois 60637, USA.
Arch Pathol Lab Med. 2009 Jul;133(7):1062-77. doi: 10.5858/133.7.1062.
Changes in the practice of diagnosing brain tumors are formally reflected in the evolution of the World Health Organization classification. Beyond this classification, the practice of diagnostic pathology is also changing with the availability of new tests and the introduction of new treatment options.
Glioblastomas, oligodendrogliomas, glioneuronal tumors, and primitive pediatric tumors are discussed in an exemplary way to illustrate these changes.
Review of relevant publications through Medline database searches.
The example of glioblastomas shows how new predictive markers may help identify subgroups of tumors that respond to certain therapy regimens. The development of new treatment strategies also leads to different questions in the assessment of brain tumors, as seen in the example of pseudoprogression or the changes in tumor growth pattern in patients taking bevacizumab. Oligodendrogliomas illustrate how the identification of 1p/19q loss as a cytogenetic aberration aids our understanding of these tumors and changes diagnostic practice but also introduces new challenges in classification. Glioneuronal tumors are an evolving group of lesions. Besides a growing list of usually low-grade entities with well-defined morphologic features, these also include more poorly defined cases in which a component of infiltrating glioma is often associated with focal neuronal elements. The latter is biologically interesting but of uncertain clinical significance. Oligodendrogliomas and glioneuronal tumors both illustrate the importance of effective communication between the pathologist and the treating oncologist in the discussion of these patients. Finally, the discussion of primitive pediatric tumors stresses the clinical importance of the distinction between different entities, like atypical teratoid rhabdoid tumor, "central" (supratentorial) primitive neuroectodermal tumor, "peripheral" primitive neuroectodermal tumor, and medulloblastoma. In medulloblastomas, the recognition of different variants is emerging as a prognostic factor that may in the future also predict therapy responsiveness.
世界卫生组织分类的演变正式反映了脑肿瘤诊断实践的变化。除了这种分类之外，诊断病理学实践也随着新检测方法的出现和新治疗方案的引入而发生变化。
以胶质母细胞瘤、少突胶质细胞瘤、神经胶质神经元肿瘤和儿童原发性肿瘤为例进行讨论，以说明这些变化。
通过检索Medline数据库对相关出版物进行综述。
胶质母细胞瘤的例子表明，新的预测标志物如何有助于识别对某些治疗方案有反应的肿瘤亚组。新治疗策略的发展也在脑肿瘤评估中引发了不同的问题，如假性进展的例子或服用贝伐单抗患者肿瘤生长模式的变化。少突胶质细胞瘤说明了将1p/19q缺失鉴定为细胞遗传学异常如何有助于我们理解这些肿瘤并改变诊断实践，但也在分类中带来了新的挑战。神经胶质神经元肿瘤是一组不断演变的病变。除了越来越多具有明确形态学特征的通常为低级别实体外，还包括一些定义更不明确的病例，其中浸润性胶质瘤成分常与局灶性神经元成分相关。后者在生物学上很有趣，但临床意义尚不确定。少突胶质细胞瘤和神经胶质神经元肿瘤都说明了病理学家与主治肿瘤学家在讨论这些患者时进行有效沟通的重要性。最后，对儿童原发性肿瘤的讨论强调了区分不同实体的临床重要性，如非典型畸胎样横纹肌样肿瘤、“中枢性”（幕上）原始神经外胚层肿瘤、“外周性”原始神经外胚层肿瘤和髓母细胞瘤。在髓母细胞瘤中，识别不同变体正成为一种预后因素，未来可能还能预测治疗反应性。
