Department of Pathology, All India Institute of Medical Sciences, New Delhi - 110029, India.
Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi - 110029, India.
Pathol Res Pract. 2020 Apr;216(4):152830. doi: 10.1016/j.prp.2020.152830. Epub 2020 Jan 20.
Biallelic loss of SMARCB1/INI1 is associated with highly aggressive malignancies, namely renal and extra-renal malignant rhabdoid tumors, and atypical teratoid/ rhabdoid tumor. Increasing availability of molecular testing and immunohistochemical stains acting as surrogate tools to genetic analysis has led to an increasing recognition of SMARCB1 loss in a variety of neoplasms. Interestingly, many of these lack the typical rhabdoid features ascribed to this group of tumors, making their identification difficult.
We describe the cytological, histological, immunohistochemical and molecular features of the first case of primary SMARCB1 (INI1)-deficient carcinoma of the thyroid gland in literature. The tumor was unique in various aspects; apart from never having been documented at this location, it showed extensive glandular differentiation, mimicking metastatic adenocarcinoma.
Awareness of this novel entity is essential to avoid misdiagnosis, and for appropriate management, especially in an era of increased feasibility of targeted therapy.
SMARCB1/INI1 双等位基因缺失与高度侵袭性恶性肿瘤有关，即肾和肾外恶性横纹肌样肿瘤和非典型畸胎瘤/横纹肌样肿瘤。随着分子检测和免疫组织化学染色作为遗传分析的替代工具的日益普及，人们越来越认识到 SMARCB1 缺失存在于多种肿瘤中。有趣的是，其中许多肿瘤缺乏归因于该肿瘤群的典型横纹肌样特征，这使得它们的识别变得困难。
我们描述了首例文献报道的甲状腺原发性 SMARCB1（INI1）缺陷型癌的细胞学、组织学、免疫组织化学和分子特征。该肿瘤在各个方面都很独特；除了从未在该部位记录过之外，它还表现出广泛的腺体分化，类似于转移性腺癌。
认识到这种新实体对于避免误诊和适当管理至关重要，尤其是在靶向治疗可行性增加的时代。
