Department of Pathology, Tottori University Hospital, Yonago 683-8504, Japan.
Department of Pathobiological Science and Technology, School of Health Science, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan.
Hum Pathol. 2017 Dec;70:92-97. doi: 10.1016/j.humpath.2017.05.024. Epub 2017 Jun 7.
SMARCA4-deficient thoracic sarcoma is a recently proposed new entity of soft tissue sarcomas with an undifferentiated round cell morphology that is diagnostically challenging. Here we report a case of this tumor where the diagnosis was established using limited samples and resources. A woman in her early 30s developed two intrathoracic masses. Biopsies for these lesions showed sheets of undifferentiated round/rhabdoid cells that retained SMARCB1 expression. Further analysis revealed a reduced SMARCA4 expression and a complete loss of SMARCA2 expression in tumor cells. Subsequent Sanger sequencing identified a nonsense c.1546A>T (p.516Lys>Ter) mutation in SMARCA4 and confirmed the diagnosis. Our case highlighted clinicopathological correlation and rational use of tissue sections for immunohistochemistry may enable to diagnose this tumor even when only limited samples are available. Recognition of this new entity is important for further understanding of the disease and the future development of specific therapies.
SMARCA4 缺陷性胸壁肉瘤是一种新近提出的软组织肉瘤新实体，具有未分化的圆形细胞形态，诊断具有挑战性。在此，我们报告了一例使用有限的样本和资源来确立诊断的该肿瘤病例。一名 30 多岁的女性患者出现两个胸腔内肿块。这些病变的活检显示出成片的未分化的圆形/横纹肌样细胞，保留了 SMARCB1 的表达。进一步的分析显示肿瘤细胞中 SMARCA4 表达减少，SMARCA2 表达完全缺失。随后的 Sanger 测序发现 SMARCA4 中的无义 c.1546A>T(p.516Lys>Ter)突变，并确认了诊断。我们的病例强调了临床病理相关性和合理使用组织切片进行免疫组织化学的重要性，即使只有有限的样本，也可以进行诊断。认识到这种新实体对于进一步了解疾病和未来开发特定疗法非常重要。
