Abstract：
SMARCA4-deficient undifferentiated tumors (SMARCA4-UT) are a newly described entity and are typically seen in the thoracic cavity. However, these tumors have been described in other body sites, including the esophagus. These tumors are rare, aggressive neoplasms, characterized by the loss of protein product of SMARCA4 (Brahma-related gene-1) and the preservation of INI1 (SMARCB1) expression. Here, we present two tumors of SMARCA4-UT of the esophagus with its microscopic appearance and immunohistochemical profile. We also include a literature review of SMARCA4-deficient tumors of the tubular gastrointestinal tract with their immunohistochemical and mismatch repair profiles for each specimen. Due to its non-specific histologic appearance and variable staining in expanded immunohistochemical panels, this tumor frequently overlaps with other tumor types, making the diagnosis of SMARCA4-UT challenging. These tumors are often associated with intestinal metaplasia of the esophagus and are thought to represent a high-grade undifferentiated transformation of a conventional esophageal adenocarcinoma. These tumors are typically associated with poor clinical outcomes and have poor response to conventional therapies. Currently, there are no standard guidelines for treatment of these tumors; however, palliative radiotherapy and systemic chemotherapy may provide benefit. More recently, immunotherapy and novel therapeutic targets have shown some promise for these patients.
摘要：
SMARCA4缺陷的未分化肿瘤（SMARCA4-UT）是一种新描述的实体，通常在胸腔中看到。然而,这些肿瘤已经在其他身体部位被描述过，包括食道.这些肿瘤很罕见,侵袭性肿瘤，以SMARCA4（婆罗门相关基因1）的蛋白质产物丢失和INI1（SMARCB1）表达的保留为特征。这里,我们介绍了两种食管SMARCA4-UT肿瘤的显微外观和免疫组织化学特征。我们还包括SMARCA4缺陷型管状胃肠道肿瘤的文献综述，以及每个样本的免疫组织化学和错配修复谱。由于其非特异性组织学外观和扩大的免疫组织化学面板中的可变染色，这种肿瘤经常与其他类型的肿瘤重叠，使SMARCA4-UT的诊断具有挑战性。这些肿瘤通常与食道的肠上皮化生有关，被认为代表了常规食管腺癌的高级未分化转化。这些肿瘤通常与差的临床结果相关,并且对常规疗法具有差的响应。目前,目前尚无治疗这些肿瘤的标准指南；然而，姑息性放疗和全身化疗可能会带来益处。最近,免疫治疗和新的治疗靶点对这些患者显示出一些希望.
