Rajeswarie R T, Rao Shilpa, Nandeesh Bevinahalli N, Yasha T Chickabasaviah, Santosh Vani
Department of Neuropathology, NIMHANS, Bangalore, India.
J Clin Pathol. 2018 Apr;71(4):323-329. doi: 10.1136/jclinpath-2017-204638. Epub 2017 Aug 11.
The WHO 2016 classification of diffuse gliomas combines histological and molecular parameters for diagnosis. However, in view of cost constraints for molecular testing, an economical working formula is essential to reach a meaningful diagnosis in a resource-limited setting. The aim of this study was to establish a practical algorithmic approach using histology and immunohistochemistry (IHC) in the classification of diffuse gliomas in such a set-up.
Diffuse gliomas of WHO grade II and III diagnosed in our institute in the year 2016 were analysed for histological and IHC features, using the markers isocitrate dehydrogenase 1 (IDH1R132H) and α thalassemia/mental retardation syndrome X-linked gene (ATRX). Fluorescence in situ hybridisation (FISH) for 1p/19q co-deletion was performed when requested.
449 diffuse gliomas (grades II/III) were included in the study. Integrating histology and IHC features, as per the WHO 2016 guidelines, we derived the following groups: Astrocytoma, IDH-mutant (A,IDH-mt, 37.2%); astrocytoma, not otherwise specified (A,NOS, 12.7%); oligoastrocytoma, NOS (OA,NOS, 4.5%); and oligodendroglioma, NOS (ODG,NOS, 45.6%). FISH was performed in a subset of ODG,NOS, OA,NOS and A,NOS gliomas. This revealed 1p/19q co-deletion in all cases of ODG,NOS, 15.8% of OA,NOS and 37.5% of A,NOS. Sequencing for rare IDH 1/2 mutations was not carried out in this study.
In a resource-limited set-up, histology with IHC (IDH1(R132H) and ATRX) form the baseline to reasonably derive four histomolecular subgroups of diffuse glioma. Of these, we recommend, OA,NOS and IDH1(R132H)-non-mt ODG,NOS to be our priority for performing 1p/19q co-deletion studies in comparison to IDH-mt ODG,NOS, and it would not be mandatory for astrocytoma. Sequencing for rare IDH mutations is advised for A,NOS and OA,NOS groups, but not for the IDH1(R132H)-non-mutant diffuse gliomas with 1p/19q co-deletion.
世界卫生组织（WHO）2016年弥漫性胶质瘤分类将组织学和分子参数结合用于诊断。然而，鉴于分子检测的成本限制，在资源有限的环境中，一种经济的工作方案对于做出有意义的诊断至关重要。本研究的目的是建立一种实用的算法方法，利用组织学和免疫组织化学（IHC）对这种情况下的弥漫性胶质瘤进行分类。
分析2016年在我们研究所诊断的WHO二级和三级弥漫性胶质瘤的组织学和IHC特征，使用异柠檬酸脱氢酶1（IDH1R132H）和α地中海贫血/智力发育迟缓综合征X连锁基因（ATRX）标记物。根据需要进行1p/19q共缺失的荧光原位杂交（FISH）检测。
449例弥漫性胶质瘤（二级/三级）纳入本研究。根据WHO 2016年指南整合组织学和IHC特征，我们得出以下分组：IDH突变型星形细胞瘤（A，IDH-mt，37.2%）；未另行指定的星形细胞瘤（A，NOS，12.7%）；未另行指定的少突星形细胞瘤（OA，NOS，4.5%）；以及未另行指定的少突胶质细胞瘤（ODG，NOS，45.6%）。对ODG，NOS、OA，NOS和A，NOS胶质瘤的一个子集进行了FISH检测。结果显示，所有ODG，NOS病例、15.8%的OA，NOS病例和37.5%的A，NOS病例存在1p/19q共缺失。本研究未对罕见的IDH 1/2突变进行测序。
在资源有限的环境中，组织学联合IHC（IDH1（R132H）和ATRX）构成合理得出弥漫性胶质瘤四个组织分子亚组的基线。其中，与IDH突变型ODG，NOS相比，我们建议将OA，NOS和IDH1（R132H）非突变型ODG，NOS作为进行1p/19q共缺失研究的优先对象，而星形细胞瘤则无需强制进行。建议对A，NOS和OA，NOS组进行罕见IDH突变的测序，但对于存在1p/19q共缺失的IDH1（R132H）非突变型弥漫性胶质瘤则无需进行。
