摘要目的:探讨间变性淋巴瘤激酶（ALK）克隆号1A4抗体在儿童髓母细胞瘤中的表达及意义。方法:采用NanoString技术和测序技术对浙江大学医学院附属儿童医院2014至2017年诊治的44例儿童髓母细胞瘤标本进行分子分型鉴定，同时应用免疫组织化学EnVision二步法检测ALK在44例髓母细胞瘤整张切片中的表达，统计分析蛋白表达与分子分型的关系。结果:患者年龄范围0.5~13.0岁，平均年龄5.8岁。男性28例，女性16例。经典型31例，促纤维增生/结节型5例，广泛结节型3例，大细胞/间变型5例。44例儿童髓母细胞瘤除3例无确切划分亚型外，其余41例中5例为WNT型，12例为SHH型，9例为Group 3型，15例为Group 4型。44例肿瘤组织中13例ALK免疫组织化学阳性，阳性率为29.5%，其中强阳性6例、弱阳性7例。ALK蛋白表达与WNT型相关（ P<0.01）。WNT型中特征性出现核旁点状阳性。 结论:ALK克隆号1A4免疫组织化学可辅助儿童髓母细胞瘤分子分型，强阳性且出现核旁点状阳性提示WNT亚型。

abstractsObjective:To investigate the immunohistochemical staining of anaplastic lymphoma kinase (ALK; clone 1A4) in pediatric medulloblastoma (MB).Methods:Molecular subtyping was performed based on the NanoString and sequencing techniques for 44 pediatric MB cases at Children′s Hospital, Zhejiang University School of Medicine from 2014 to 2017. ALK expression was detected with EnVision immunhistochemistry using ALK clone 1A4 on whole section. Statistical analyses were performed to evaluate the correlation of protein expression with molecular subgroups.Results:The age ranged from 0.5 to 13.0 years with an average age of 5.8 years. There were 28 males and 16 females, and 31 classic, 5 desmoplastic nodular, 3 extensive nodular and 5 large cell/anaplastic MBs. Except three cases was unable classified, 41 MBs were classified into the four molecular groups: 5 in WNT group, 12 in SHH group, 9 in Group 3 and 15 in Group 4. Thirteen of 44 MB cases were positive staining for ALK, and the positive rate was 29.5%. Six cases were strong reaction, and 7 cases were weak. The expression of ALK at the protein level was associated with the WNT group ( P<0.01). The characteristic perinuclear dot-like staining was only showed in WNT group. Conclusions:The ALK immunhistochemistry using antibody clone 1A4 is a useful marker for the molecular subgroup detection of MB. The strong staining and perinuclear dot-like staining indicate as WNT group.