中枢神经系统非典型畸胎样/横纹肌样瘤2例的临床病理特征及文献复习

Clinicopathological features of atypical teratoid/rhabdoid tumor of central nervous system: a report of two cases and literature review

目的中枢神经系统非典型畸胎样/横纹肌样瘤(AT/RT)是少见的儿童胚胎性肿瘤,成人偶有发生。本研究通过报道1例儿童及1例成人AT/RT,探讨其临床病理特征、诊断及鉴别诊断方法。方法对2例AT/RT行HE及免疫组织化学染色观察,结合文献复习对其形态学及免疫表型特征进行分析。结果儿童(3岁)AT/RT 1例,MRI示右额颞叶混杂密度影;成人(33岁)AT/RT 1例,MRI示鞍区不均匀强化影,临床疑为垂体肿瘤。2例镜下均主要由横纹肌样细胞组成,伴有多少不等的原始神经外胚层肿瘤样成分。免疫组化显示Vim弥漫强阳性,GFAP、S-100、Syn、NF、CK、EMA、SMA、Desmin、MyoD1均有不同程度阳性,PLAP、HMB45阴性。结论 AT/RT是一高度恶性的中枢神经系统肿瘤,成人与儿童AT/RT在形态学及免疫组化特征上无明显差别,但成人在发病年龄、部位和预后上均与儿童有所不同,更易造成误诊,鉴别诊断侧重点也与儿童不同,需引起更多注意。

Objective Atypical teratoid/rhabdoid tumor （AT/RT） is a rare embryonic tumor of central nervous system in infants and young children, and it is extremely rare in adult and more difficult to diagnose. This paper reports 2 cases of AT/RT in children and adult, respectively, to study the clinicopathological characteristics and the method of diagnosis and differential diagnosis of AT/RT. Methods The two cases of AT/RT were observed by immunohistochemistry and HE staining, and the features of morpbology and immunophenotype were analyzed by combining with literature review. Results Case 1：3 years old; MRI showed right frontotemporal lobar heterogeneously enhancing mass. Case 2 ： 33 years old; MRI showed heterogeneously enhancing mass of sella region which was suspicious of pituitary adenoma by clinician. Histologically, both of the two AT/RT cases were mainly consisted of rhabdoid ceils associated with more or less PNET-Iike component under microscope. Immunohistochemistry showed that Vim was diffuse strong positive ; GFAP, S-IO0, Syn, NF, CK, EMA, SMA, Desmin and MyoD1 were different degrees positive; PLAP and HMIM5 was negative. Conclusions AT/RT is a highly aggressive tumor of central nerveous system. The features of morphology and immunohistochemistry in adult and children show no significant difference. Duo to the onset age,position and prognosis in adult are different with those in children, AT/RT in adult is more likely to cause misdiagnosis. The emphasis of differential diagnosis in adult is also different with that in children, and this should pay more attention.