Ulzen-Appiah Kofi, Akakpo Kafui Patrick
Cape Coast Teaching Hospital, Department of Pathology, Cape Coast, Ghana.
Autops Case Rep. 2022 Apr 14;12:e2021373. doi: 10.4322/acr.2021.373. eCollection 2022.
Embryonal tumor with multilayered rosettes (ETMR), NOS/C19MC- altered, is a rare and recently classified highly aggressive malignant brain tumor in the 2021 World Health Organization (WHO) classification of tumors of the central nervous system 5 edition. They are mostly diagnosed in children before the age of three years. Most of them are located in the supratentorial region. Prior to the reclassification of ETMR as a single entity, three distinct tumors, namely, embryonal tumor with abundant neuropil and true rosettes (ETANTR), ependymoblastoma (EBL) and medulloepithelioma (MEPL) were recognized. Recent studies showed that all the three entities have multilayered rosettes on morphology, sharing a common amplification of the C19MC locus at the chromosome 19q13.42 by fluorescence in situ hybridization, and highly specific immunohistochemical staining for LIN28A rendered their reclassification as a single entity.
A 13-year-old girl was rushed to the emergency room unconscious, with no return of spontaneous circulation after cardiopulmonary resuscitation. Autopsy revealed a left cerebellar hemisphere hemorrhagic tumor which histopathological examination revealed a multilayered ependymoblastic rosettes with abundant neuropil. The multilayered rosettes showed reactivity for vimentin but non-reactivity for pan-cytokeratin, the zones with abundant neuropil were reactive for synaptophysin consistent with a diagnosis of embryonal tumor with abundant neuropil and true rosettes now ETMR, NOS (WHO Grade 4) due to the lack of genetic testing for amplification of C19MC.
ETMR is a highly aggressive CNS embryonal tumor with extremely poor prognosis. It should be considered in the differential diagnosis of pediatric brain tumors. Multilayered rosettes are a useful clue to histologic diagnosis.
具有多层菊形团的胚胎性肿瘤（ETMR），NOS/C19MC改变型，是一种罕见的、近期分类的高度侵袭性恶性脑肿瘤，在2021年世界卫生组织（WHO）中枢神经系统肿瘤分类第5版中有所描述。它们大多在3岁前的儿童中被诊断出来。大多数位于幕上区域。在将ETMR重新分类为单一实体之前，曾识别出三种不同的肿瘤，即具有丰富神经毡和真性菊形团的胚胎性肿瘤（ETANTR）、室管膜母细胞瘤（EBL）和髓上皮瘤（MEPL）。最近的研究表明，这三种实体在形态学上均具有多层菊形团，通过荧光原位杂交在染色体19q13.42处共享C19MC基因座的共同扩增，并且LIN28A的高度特异性免疫组化染色使其重新分类为单一实体。
一名13岁女孩被紧急送往急诊室时已昏迷，心肺复苏后未恢复自主循环。尸检发现左小脑半球有一个出血性肿瘤，组织病理学检查显示为具有丰富神经毡的多层室管膜母细胞菊形团。多层菊形团对波形蛋白呈阳性反应，但对泛细胞角蛋白呈阴性反应，具有丰富神经毡的区域对突触素呈阳性反应，由于缺乏C19MC扩增的基因检测，符合具有丰富神经毡和真性菊形团的胚胎性肿瘤的诊断，现称为ETMR，NOS（WHO 4级）。
ETMR是一种高度侵袭性的中枢神经系统胚胎性肿瘤，预后极差。在小儿脑肿瘤的鉴别诊断中应考虑到它。多层菊形团是组织学诊断的有用线索。
