促纤维增生性小圆细胞肿瘤(desmoplastic small round cell tumor,DSRCT)为一种极罕见、高度恶性的软组织肉瘤。除偶然发现外,多数患者确诊时已为晚期。DSRCT主要发生于腹盆腔,沿腹膜表面播散,多数患者确诊时已失去手术机会。DSRCT的诊...促纤维增生性小圆细胞肿瘤(desmoplastic small round cell tumor,DSRCT)为一种极罕见、高度恶性的软组织肉瘤。除偶然发现外,多数患者确诊时已为晚期。DSRCT主要发生于腹盆腔,沿腹膜表面播散,多数患者确诊时已失去手术机会。DSRCT的诊断是基于组织学检查,典型的表现为癌巢中的小圆蓝色细胞被大量的纤维增生性基质分隔开。特征性的t(11;22)(p13;q12)染色体异位产生EWSR1-WT1融合基因是DSRCT稳定存在的遗传学特点。该病预后极差,5年生存率仅约15%,主要由于肿瘤发生转移所致。DSRCT的治疗仍然具有挑战性,尽管使用了积极的治疗方法,如化疗、手术和全腹部放疗等,但60%~70%患者在2~3年内死亡。随着对DSRCT分子遗传学的研究不断深入,靶向治疗、免疫治疗等方法近年开始尝试应用于DSRCT的治疗。展开更多
Desmoplastic small round cell tumor(DSRCT) is a rare,aggressive malignant neoplasm of unknown origin, and is comprised of small round cells with a characteristic desmoplastic stroma. DSRCT typically expresses epitheli...Desmoplastic small round cell tumor(DSRCT) is a rare,aggressive malignant neoplasm of unknown origin, and is comprised of small round cells with a characteristic desmoplastic stroma. DSRCT typically expresses epithelial, mesenchymal and neural markers simultaneously. We describe a case of DSRCT with an atypical immunohistochemical profile and rhabdoid-like tumor cells on electron microscopy. In the present case, the neoplastic cells were positive only for vimentin, desmin(cytoplasmic membranous pattern) and CD56,and negative for smooth muscle actin, synaptophysin,CD117, CD45, myogenin, CAM5.2, pancytokeratin,WT1, EMA, CD99, neurofilament, CD34 and p53. Ki67 showed a low proliferative activity. Electron microscopy showed focal rhabdoid differentiation. However, INI-1(SNF-5/BAF47) demonstrated preservation of nuclear positivity in the neoplastic cells. Cytogenetic studies showed translocation t(11;22)(p13;q12) confirming an EWSR1-WT1 translocation characteristic for DSRCT, and t(1;15)(q11;p11.2) of unknown significance. This case is a diagnostic challenge because of atypical immunohistochemical profile and cytogenetic study is crucial in rendering the correct diagnosis.展开更多
文摘促纤维增生性小圆细胞肿瘤(desmoplastic small round cell tumor,DSRCT)为一种极罕见、高度恶性的软组织肉瘤。除偶然发现外,多数患者确诊时已为晚期。DSRCT主要发生于腹盆腔,沿腹膜表面播散,多数患者确诊时已失去手术机会。DSRCT的诊断是基于组织学检查,典型的表现为癌巢中的小圆蓝色细胞被大量的纤维增生性基质分隔开。特征性的t(11;22)(p13;q12)染色体异位产生EWSR1-WT1融合基因是DSRCT稳定存在的遗传学特点。该病预后极差,5年生存率仅约15%,主要由于肿瘤发生转移所致。DSRCT的治疗仍然具有挑战性,尽管使用了积极的治疗方法,如化疗、手术和全腹部放疗等,但60%~70%患者在2~3年内死亡。随着对DSRCT分子遗传学的研究不断深入,靶向治疗、免疫治疗等方法近年开始尝试应用于DSRCT的治疗。
基金Supported by Department of Pathology,the University of Texas Health Science Center at Houston,United States
文摘Desmoplastic small round cell tumor(DSRCT) is a rare,aggressive malignant neoplasm of unknown origin, and is comprised of small round cells with a characteristic desmoplastic stroma. DSRCT typically expresses epithelial, mesenchymal and neural markers simultaneously. We describe a case of DSRCT with an atypical immunohistochemical profile and rhabdoid-like tumor cells on electron microscopy. In the present case, the neoplastic cells were positive only for vimentin, desmin(cytoplasmic membranous pattern) and CD56,and negative for smooth muscle actin, synaptophysin,CD117, CD45, myogenin, CAM5.2, pancytokeratin,WT1, EMA, CD99, neurofilament, CD34 and p53. Ki67 showed a low proliferative activity. Electron microscopy showed focal rhabdoid differentiation. However, INI-1(SNF-5/BAF47) demonstrated preservation of nuclear positivity in the neoplastic cells. Cytogenetic studies showed translocation t(11;22)(p13;q12) confirming an EWSR1-WT1 translocation characteristic for DSRCT, and t(1;15)(q11;p11.2) of unknown significance. This case is a diagnostic challenge because of atypical immunohistochemical profile and cytogenetic study is crucial in rendering the correct diagnosis.
