Bookhout Christine, Bouldin Thomas W, Ellison David W
Department of Surgical Pathology, University of North Carolina, Chapel Hill, North Carolina, USA.
Department of Neuropathology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
Neuropathology. 2018 Jun;38(3):305-308. doi: 10.1111/neup.12452. Epub 2017 Dec 21.
Atypical teratoid/rhabdoid tumor (AT/RT) is a rare, highly aggressive malignancy of the central nervous system (CNS) usually diagnosed in infancy or childhood, most often characterized by loss of expression of the SMARCB1 gene product integrase interactor 1 (INI1) protein. We report a case of AT/RT in a 3 month old boy with retained expression of INI1 by immunohistochemistry. Additional testing demonstrated loss of expression of the SMARCA4 gene product Brahma-related gene 1 (BRG1) protein by immunohistochemistry, confirmed by next generation sequencing showing a nonsense mutation in SMARCA4. This case illustrates that positivity for INI1 does not rule out a diagnosis of AT/RT, and additional testing, including BRG1/SMARCA4 analysis, is warranted in cases where clinical suspicion is high.
非典型畸胎样/横纹肌样瘤（AT/RT）是一种罕见的、侵袭性很强的中枢神经系统（CNS）恶性肿瘤，通常在婴儿期或儿童期被诊断出来，其最常见的特征是SMARCB1基因产物整合酶相互作用因子1（INI1）蛋白表达缺失。我们报告了一例3个月大男孩患AT/RT的病例，通过免疫组织化学检测发现其INI1表达保留。进一步检测显示，通过免疫组织化学检测，SMARCA4基因产物布拉马相关基因1（BRG1）蛋白表达缺失，下一代测序证实SMARCA4存在无义突变。该病例表明，INI1呈阳性并不能排除AT/RT的诊断，在临床怀疑度高的病例中，有必要进行包括BRG1/SMARCA4分析在内的进一步检测。
