Simons J, Teshima I, Zielenska M, Edwards V, Taylor G, Squire J, Thorner P
Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, University of Toronto, Canada.
Am J Surg Pathol. 1999 Aug;23(8):982-8. doi: 10.1097/00000478-199908000-00018.
Malignant rhabdoid tumor is a highly aggressive tumor of childhood that may present as a soft-tissue primary tumor. We report a soft-tissue neoplasm that was polyphenotypic by immunohistochemical expression of epithelial, mesenchymal, and neural markers and did not meet the criteria for any of the usual pediatric small round-cell tumors. The findings raised the diagnosis of rhabdoid tumor, leading to testing for WT1 mRNA and protein expression, which were positive, as has been reported for renal rhabdoid tumor. This tumor had the typical clinical behavior of rhabdoid tumor with therapy resistance and early tumor-related death. Multicolor spectral karyotyping of this neoplasm showed a balanced translocation between chromosomes 1 and 22 with breakpoints at 1p36 and 22q11-12. The latter region is commonly involved in rhabdoid tumor. This change was also identified by fluorescence in situ hybridization. This case suggests that studies of chromosome 22 may be required to distinguish rhabdoid tumor from other soft-tissue tumors.
恶性横纹肌样瘤是一种儿童期高侵袭性肿瘤，可表现为软组织原发性肿瘤。我们报告了一例软组织肿瘤，通过上皮、间充质和神经标志物的免疫组化表达呈多表型，且不符合任何常见儿童小圆细胞肿瘤的标准。这些发现提示横纹肌样瘤的诊断，进而检测WT1 mRNA和蛋白表达，结果呈阳性，这与肾横纹肌样瘤的报道一致。该肿瘤具有横纹肌样瘤典型的临床行为，即对治疗耐药且早期因肿瘤死亡。该肿瘤的多色光谱核型分析显示1号和22号染色体之间存在平衡易位，断点位于1p36和22q11 - 12。后一区域在横纹肌样瘤中常受累。荧光原位杂交也鉴定出了这种变化。该病例提示，可能需要对22号染色体进行研究，以将横纹肌样瘤与其他软组织肿瘤区分开来。
