Peterson Jo Elle G, Bavle Abhishek, Mehta Vidya P, Rauch Ronald A, Whitehead William E, Mohila Carrie A, Su Jack M, Adesina Adekunle M
1 Department of Pathology, College of Medicine, University of Oklahoma, Oklahoma City, Oklahoma.
2 Section of Pediatric Hematology/Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
Pediatr Dev Pathol. 2019 Mar-Apr;22(2):161-165. doi: 10.1177/1093526618814696. Epub 2018 Nov 23.
Atypical teratoid/rhabdoid tumor (ATRT) is a high-grade central nervous system tumor, with poor prognosis despite intensive multimodal therapy. Loss of nuclear immunostaining for INI1 due to inactivation of the hSNF5/INI1 tumor suppressor gene is pathognomonic of ATRT. We present a patient with congenital ATRT, who had spontaneous tumor regression without therapy, and is disease-free 4 years later. Tumor histopathology showed rhabdoid cells characteristic of ATRT, but immunohistochemistry revealed heterogeneous loss of nuclear INI1 staining. The populations of INI1-intact and INI1-deficient cells were separated by laser microdissection, for molecular analysis with DNA sequencing and fluorescence in situ hybridization. The INI1-negative cells were found to harbor a heterozygous deletion and truncating mutation of the hSNF5/INI1 locus, while the INI1-intact cells had 2 copies of the wild-type INI1 gene. To our knowledge, this is the first report of spontaneous regression of ATRT, with molecular heterogeneity for SMARCB1 inactivation, with no radiographic signs of recurrence at 4 years after diagnosis.
非典型畸胎样/横纹肌样瘤（ATRT）是一种高级别中枢神经系统肿瘤，尽管采用了强化多模式治疗，预后仍较差。由于hSNF5/INI1肿瘤抑制基因失活导致INI1核免疫染色缺失是ATRT的特征性表现。我们报告了一名患有先天性ATRT的患者，其肿瘤未经治疗便自发消退，4年后无疾病迹象。肿瘤组织病理学显示出ATRT特征性的横纹肌样细胞，但免疫组化显示核INI1染色存在异质性缺失。通过激光显微切割分离出INI1完整和INI1缺陷的细胞群体，用于DNA测序和荧光原位杂交的分子分析。发现INI1阴性细胞存在hSNF5/INI1基因座的杂合缺失和截短突变，而INI1完整的细胞有2个野生型INI1基因拷贝。据我们所知，这是ATRT自发消退的首例报告，其SMARCB1失活具有分子异质性，诊断后4年无影像学复发迹象。
