儿童腺泡状软组织肉瘤13例临床病理学特征

目的探讨儿童腺泡状软组织肉瘤(alveolar soft part sarcoma,ASPS)的临床病理、分子遗传学特点、诊断及鉴别诊断。方法对北京儿童医院2009年8月至2018年11月13例儿童ASPS病例存档切片行HE染色及组织化学染色包括过碘酸-雪夫(PAS)染色及淀粉酶消化PAS(D-PAS染色)]。采用免疫组织化学染色检测TFE3、INI1、CD68等的表达,应用荧光原位杂交(FISH)法检测TFE3基因断裂易位情况。结果13例ASPS中,男童4例,女童9例,年龄1岁2个月至13岁8个月,平均7.8岁,5岁以下4例。组织学上,11例肿瘤细胞呈腺泡状、巢状排列,2例肿瘤细胞呈实性、弥漫性生长。瘤细胞胞质嗜酸性,可见明显的空泡现象,核多形性,核仁突出,核分裂象罕见,3例可见血管浸润。免疫组织化学染色TFE3弥漫核阳性,INI1、CD68、波形蛋白阳性,MyoD1、Myogenin、细胞角蛋白、S-100蛋白等均阴性。7例PAS及D-PAS染色显示肿瘤细胞质内均可见紫红色针状或棒状结晶体。9例行FISH检测,均显示TFE3基因断裂易位。结论ASPS为儿童少见软组织肿瘤,肿瘤多位于深部肌肉内,瘤细胞排列成腺泡状或巢状,同时TFE3基因位点发生断裂易位,确定诊断需要结合临床、病理形态、免疫组织化学及基因检测综合考虑。

Alveolar soft part sarcoma in children: a clinicopathological study of 13 cases

Objective To investigate the clinicopathological manifestations,molecular genetic,diagnostic histology and differential diagnosis of alveolar soft part sarcoma(ASPS)in children.Methods A total of 13 cases of ASPS diagnosed at Beijing Children′s Hospital from August 2009 to November 2018 were collected.HE staining,histochemical staining for PAS and D-PAS,immunohistochemical(IHC)staining for TFE3,INI1 and CD68 and florescence in situ hybridization(FISH)for TFE3 gene translocation were performed.Results There were four males and nine females,age ranged from 1 year and 2 months to 13 years and 8 months(mean 7.8 years);and four patients were under 5 years old.Histologically,the tumors showed a distinctive and characteristic nested or organoid growth pattern(11 cases)or solid,diffuse growth(2 cases).The tumor cells possessed abundant eosinophilic,or glycogen-rich and clear to vacuolated cytoplasm.The chromatin was relatively dispersed,with prominent and pleomorphic nucleoli;mitotic figures were rare.Vascular invasion was frequently seen.IHC staining showed specific nuclear TFE3 staining.The tumor cells were also positive for INI1,CD68 and vimentin;but were negative for MyoD1,Myogenin,CK and S-100 protein.Seven cases showed PAS and D-PAS staining,with fuchsia acicular or rod-shaped crystals in tumor cytoplasm.Nine cases showed TFE3 break-apart signals by FISH.Conclusions ASPS is a rare soft tissue sarcoma in children.Compared with ASPA in adults,it has both similarities and unique clinicopathologic characteristics.The diagnosis needs to be confirmed by combining clinical,pathologic,IHC and genetic testing.