Asif Amna, Mushtaq Sajid, Hassan Usman, Akhtar Noreen, Hussain Mudassar, Azam Muhammad, Qazi Romena
Department of Pathology, Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan. Emaile:
Asian Pac J Cancer Prev. 2018 Mar 27;19(3):655-660. doi: 10.22034/APJCP.2018.19.3.655.
Introduction:Soft tissue sarcomas are rare tumors comprising 1 percent of solid malignancies. The latest edition of WHO soft tissue pathology lists 94 benign and malignant soft tissue tumors. Many of these show a large degree of morphological overlap. Immunohistochemistry has been shown to be reliable in many cases for differential diagnosis of lesions, although cytogenetic tests are considered the gold standard for many entities.Fluorescence in-situ hybridization (FISH) is a cytogenetic technique that uses fluorescent probes that bind to only those parts of the chromosome which have a high degree of sequence complementarity. Many soft tissue tumors show recurrent genetic mutations that are now being used as diagnostic markers. Knowledge of the molecular identity allows prediction of behavior, prognosis and treatment response. Objective:The aim of this study was to identify genetic mutations in soft tissue sarcomas using FISH testing and to assess correlations with histological diagnosis. Material and methods:A total of 25 cases of different soft tissue sarcomas diagnosed on histology with the help of immunohistochemical staining and for which FISH studies were requested were included in this study. Three pathologists with a special interest in soft tissue sarcomas reviewed the cases. FISH tests for EWS, the X:18 translocation, FOXO1 and MDM2 were respectively applied for 8 cases of Ewing sarcoma, 8 cases of synovial sarcoma, 2 cases of rhabdomyosarcoma and 7 cases of dedifferentiated liposarcoma and atypical lipomatous tumors/well differentiated liposarcomas. Results:EWS gene fusion was detected in 7 out of 8 cases of Ewing sarcoma and the X:18 translocation was positive in 3 of the 8 cases of synovial sarcoma. FOXO1 was not detected in either of the two rhabdomyosarcomas. MDM2 by FISH was detected in only one out of 5 cases of atypical lipomatous tumors and 1 out of 2 dedifferentiated liposarcomas. Conclusion: FISH is a useful adjunct in the diagnostic assessment of different types of soft tissue sarcomas. It is easy to set up, is relatively inexpensive and has the ability to diagnose sarcomas with great accuracy, especially in cases which can not be accurately classified even after thorough histological and immunohistochemical evaluation. It may play a very important role in the accurate diagnosis and correct management of patients.
软组织肉瘤是罕见肿瘤，占实体恶性肿瘤的1%。世界卫生组织软组织病理学最新版列出了94种良性和恶性软组织肿瘤。其中许多肿瘤在形态学上有很大程度的重叠。免疫组织化学在许多病例中已被证明对病变的鉴别诊断可靠，尽管细胞遗传学检测被认为是许多实体肿瘤的金标准。荧光原位杂交（FISH）是一种细胞遗传学技术，它使用荧光探针，这些探针仅与染色体上具有高度序列互补性的部分结合。许多软组织肿瘤显示出复发性基因突变，这些突变现在正被用作诊断标志物。了解分子特征有助于预测肿瘤行为、预后和治疗反应。目的：本研究旨在使用FISH检测鉴定软组织肉瘤中的基因突变，并评估其与组织学诊断的相关性。材料和方法：本研究共纳入25例经免疫组织化学染色组织学诊断的不同软组织肉瘤病例，并要求进行FISH研究。三位对软组织肉瘤有特殊兴趣的病理学家对这些病例进行了复查。分别对8例尤因肉瘤、8例滑膜肉瘤、2例横纹肌肉瘤以及7例去分化脂肪肉瘤和非典型脂肪瘤/高分化脂肪肉瘤进行EWS、X:18易位、FOXO1和MDM2的FISH检测。结果：8例尤因肉瘤中有7例检测到EWS基因融合，8例滑膜肉瘤中有3例X:18易位呈阳性。2例横纹肌肉瘤均未检测到FOXO1。在5例非典型脂肪瘤和2例去分化脂肪肉瘤中，FISH检测仅在1例中检测到MDM2。结论：FISH是不同类型软组织肉瘤诊断评估中的有用辅助手段。它易于设置，相对便宜，并且能够非常准确地诊断肉瘤，尤其是在经过全面的组织学和免疫组织化学评估后仍无法准确分类的病例中。它可能在患者的准确诊断和正确管理中发挥非常重要的作用。
