儿童中枢神经系统郎格汉斯细胞组织细胞增生症的MRI表现

MRI features of Langerhans cell histiocytosis in central nervous system in children

目的探讨儿童中枢神经系统郎格汉斯细胞组织细胞增生症（LCH）的MRI表现。方法回顾性分析2009年1月至2014年12月3家儿童医院经手术或穿刺活检证实的中枢神经系统LCH病例25例，所有病例均行垂体和（或）头颅MR平扫及增强扫描。重点观察神经系统受累病灶部位、形态、MRI信号变化及强化情况。结果下丘脑垂体病变17例，其中2例合并松果体囊肿，2例合并脑实质病变，1例合并松果体囊肿和脑实质病变。MRI表现为垂体后叶T1WI正常高信号均消失，垂体柄呈结节状或均匀增粗。硬脑膜病变3例，单发2例、多发1例；脉络丛肿块1例，位于左侧脑室三角区内。松果体病变3例，主要表现为松果体区类圆形囊性病变。灰质病变4例，其中2例单独累及小脑齿状核，2例同时累及丘脑和基底节区。白质病变3例；无明显的Virchow-Robin腔扩大和脑萎缩。结论中枢神经系统LCH病变的影像表现有一定特征性，诊断时应结合临床表现全面分析，综合判断。

Objective To explore the MRI features of Langerhans cell histiocytosis （LCH） in central nervous system （CNS） in children. Methods Clinical and MRI data of 25 cases with LCH in CNS from three children＇s hospitals between January 2009 and December 2014 were retrospectively studied. All cases were confirmed by surgelT or biopsy. All cases underwent non-contrast and contrast pituitary and/or cranial MRI examinations. The location, morphology, MRI signal and enhanced patterns of LCH lesions were observed and analyzed. Result A total of 17 cases had hypothalamic-pituitary LCH, with 2 of them complicated with pineal cyst, 2 complicated with brain parenchymal lesions, and one complicated with both pineal cyst and brain parenchymal lesions. MR images showed that neurohypophysis lost its original hyperintensity on T1WI, and nodular or homogeneous thickening was seen in the pituitary stalks. Dura matter was involved in 3 cases, 2 of them had single lesion, and the other one got multiple lesions. Neoplasm in choroid plexus was seen in trigone of left lateral ventricles in one case. Three cases with pineal gland involved demonstrated cystic change. Four cases had gray matter involved, with eerebellar dentate nuclei involvement in 2 cases, and both thalamus and basal ganglia involvement in the other two cases. Three cases showed white matter involvement without obvious Virchow-Robin space enlargement and brain atrophy. Conclusions MR imaging of LCH in CNS shows certain specific characteristics. The diagnosis can be made comprehensively based on both clinic features and other imaging findings.