Agaimy Abbas
Institute of Pathology, University Hospital, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany.
Adv Anat Pathol. 2014 Nov;21(6):394-410. doi: 10.1097/PAP.0000000000000038.
Since the description of atypical teratoid/rhabdoid tumors of the central nervous system and renal/extrarenal malignant rhabdoid tumors in children, the clinicopathologic spectrum of neoplasms having in common a highly variable rhabdoid cell component (0% to 100%) and consistent loss of nuclear SMARCB1 (INI1) expression has been steadily expanding to include cribriform neuroepithelial tumor of the ventricle, renal medullary carcinoma and a subset of collecting duct carcinoma, epithelioid sarcoma, subsets of miscellaneous benign and malignant soft tissue tumors, and rare rhabdoid carcinoma variants of gastroenteropancreatic, sinonasal, and genitourinary tract origin. Although a majority of SMARCB1-deficient neoplasms arise de novo, the origin of SMARCB1-deficient neoplasia in the background of a phenotypically or genetically definable differentiated SMARCB1-intact "parent neoplasm" has been convincingly demonstrated, highlighting the rare occurrence of rhabdoid tumors as "double-hit neoplasia." As a group, SMARCB1-deficient neoplasms occur over a wide age range (0 to 80 y), may be devoid of rhabdoid cells or display uniform rhabdoid morphology, and follow a clinical course that varies from benign to highly aggressive causing death within a few months irrespective of aggressive multimodality therapy. Generally applicable criteria that would permit easy recognition of these uncommon neoplasms do not exist. Diagnosis is based on site-specific and entity-specific sets of clinicopathologic, immunophenotypic, and/or molecular criteria. SMARCB1 immunohistochemistry has emerged as a valuable tool in confirming or screening for SMARCB1-deficient neoplasms. This review summarizes the different phenotypic and topographic subgroups of SMARCB1-deficient neoplasms including sporadic and familial, benign and malignant, and rhabdoid and nonrhabdoid variants, highlighting their phenotypic heterogeneity and molecular complexity.
自从中枢神经系统非典型畸胎样/横纹肌样肿瘤以及儿童肾/肾外恶性横纹肌样肿瘤被描述以来，具有高度可变横纹肌样细胞成分（0%至100%）且核SMARCB1（INI1）表达持续缺失的肿瘤的临床病理谱一直在稳步扩展，包括脑室筛状神经上皮肿瘤、肾髓质癌和集合管癌的一个子集、上皮样肉瘤、各种良性和恶性软组织肿瘤的子集，以及起源于胃肠胰、鼻窦和泌尿生殖道的罕见横纹肌样癌变体。尽管大多数SMARCB1缺陷型肿瘤是新发的，但在表型或基因可定义的分化型SMARCB1完整的“母肿瘤”背景下，SMARCB1缺陷型肿瘤形成的起源已得到令人信服的证明，这突出了横纹肌样肿瘤作为“双打击肿瘤”的罕见性。作为一个群体，SMARCB1缺陷型肿瘤发生在广泛的年龄范围内（0至80岁），可能没有横纹肌样细胞或呈现一致的横纹肌样形态，并且临床病程从良性到高度侵袭性不等，无论采用何种积极的多模式治疗，都可能在几个月内导致死亡。不存在能够轻松识别这些罕见肿瘤的普遍适用标准。诊断基于特定部位和特定实体的临床病理、免疫表型和/或分子标准组合。SMARCB1免疫组化已成为确认或筛查SMARCB1缺陷型肿瘤的有价值工具。本综述总结了SMARCB1缺陷型肿瘤的不同表型和部位亚组，包括散发性和家族性、良性和恶性以及横纹肌样和非横纹肌样变体，突出了它们的表型异质性和分子复杂性。
