- 研究队列包括 42 例具毛细胞样特征高级别星形细胞瘤（HGAP）与多形性黄色星形细胞瘤（PXA）；11/12 例 HGAP 和 28/30 例 PXA 存在纯合缺失（HD）。
- 本队列中，p16/MTAP IHC 与 FISH、甲基化谱衍生拷贝数分析及 SNP 芯片检测结果高度一致，敏感度和特异度均为 100%。
- 联合 p16/MTAP IHC 对检出 HD 具有阳性预测价值，可辅助局限性胶质／胶质神经元肿瘤的诊断评估。
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摘要
CDKN2A 纯合缺失（HD）的存在，在神经病理医师对多种中枢神经系统（CNS）肿瘤的诊断评估中具有重要作用。CDKN2A 位于染色体 9p21，邻近 CDKN2B 和 MTAP，编码 p16 蛋白。CDKN2A/B HD 是某些局限性胶质瘤中的常见改变，例如具毛细胞样特征高级别星形细胞瘤（HGAP）和多形性黄色星形细胞瘤（PXA）。这些肿瘤类型的诊断仍然复杂，若能有一种快速、简便的工具提示这些诊断，将具有实用价值。本研究纳入 42 例 HGAP 和 PXA，分析三种不同分子技术（FISH、可提供拷贝数变异分析的 DNA 甲基化谱分析，以及 SNP 芯片）对 CDKN2A/B 和 MTAP 状态检测的一致性，并将结果与 p16 和 MTAP 免疫组织化学结果比较。11/12 例 HGAP 和 28/30 例 PXA 存在 HD，但缺失片段大小差异很大，涉及 CDKN2A、CDKN2B 和 MTAP 基因。p16/MTAP 免疫表达与遗传学检测 HD 之间具有极佳的一致性，敏感度和特异度均为 100%。综上，联合 p16/MTAP IHC 对检出 HD 具有阳性预测价值，可辅助神经病理医师对局限性胶质／胶质神经元肿瘤进行诊断评估。
PubMed abstract only. Full text and full-text figures or tables were not collected because of OUP access restrictions.
Abstract
The presence of a CDKN2A homozygous deletion (HD) plays an important role in the diagnostic approach of neuropathologists to several central nervous system (CNS) tumors. CDKN2A is located on chromosome 9p21, next to CDKN2B and MTAP, and encodes for the protein p16. CDKN2A/B HD constitutes a frequent alteration in some circumscribed gliomas such as high-grade astrocytomas with piloid features (HGAP) and pleomorphic xanthoastrocytomas (PXA). The diagnosis of these tumor types remains complex and having a rapid and easy tool to suggest these diagnoses would be useful. Herein, we studied a cohort of 42 HGAP and PXA to analyze the concordance of CDKN2A/B and MTAP status between 3 different molecular techniques (FISH, DNA-methylation profiling providing copy number variation analysis, and SNP array), and compared the results to those of p16 and MTAP immunohistochemistry. HD was present in 11/12 HGAP and 28/30 PXA, however, with a wide variety of deletion size, including of CDKN2A, CDKN2B, and MTAP genes. There was excellent concordance between p16/MTAP immunoexpression and the genetic detection of HD, demonstrating 100% sensitivity and 100% specificity. In conclusion, combined p16/MTAP IHC presented a positive predictive value for detecting HD and may assist neuropathologists in their diagnostic approach to circumscribed glial/glioneuronal tumors.