直接侵犯肝胆的儿童朗格汉斯细胞组织细胞增生症CT和MRI特征

CT and MRI Findings of Hepatobiliary Direct Involvement in Langerhans Cell Histiocytosis in Children

【目的】探讨直接侵犯肝胆的儿童朗格汉斯细胞组织细胞增生症（LCH）影像特征。【方法】回顾性分析经病理证实7例LCH患者腹部CT和MRI资料。【结果】7例LCH肝脏侵犯者表现为肝脏弥漫性增大，病灶为多发，弥漫分布在肝脏各叶，1例累及包膜下肝脏组织，大多呈圆形或类圆形，边缘模糊，大小不等，大者直径约25mm，小者如米粒大，沿门脉主干周围和肝边缘分布结节相互融合呈串珠状。CT平扫呈低密度，增强后较大病灶周边明显强化范围缩小，较小病灶明显强化呈等密度。延时后扫描大部分病灶明显强化，呈等密度或高密度。MRI扫描呈长T1长T2信号，DWI呈高信号，ADC图呈低信号；增强后病灶明显强化呈等信号，部分呈高信号。5例胆管侵犯者表现胆管壁不均匀性增厚，明显强化，胆管呈囊状或管状扩张，大部分位于肝内侵犯病灶中央。4例肝门区淋巴结增大，脾大3例，1例胆囊周围积液。【结论】儿童LCH肝胆直接侵犯见于多系统多灶性LCH，影像学检查结合临床有助于对该病的诊断，确诊有赖于病理检查。

[Objective] To explore the imaging features of hepatobiliary direct involvement in Langerhans cell histiocytosis（LCH） in children. [Methods] The data of CT and MRI of 7 children with hepatobiliary di- rect involvement in LCH confirmed by pathology were analyzed retrospectively. [Results] Seven patients with liver direct involvement showed diffuse enlargement of liver, multiple lesions distributed in all liver lobes. One patient with subcapsular liver tissue involvement showed that the liver was round or oval with vague boundary and uneven size ranged from the size of granule to 25ram in diameter, and portal main stem surrounding was fused with hepatic margin-distributed node like the bead. Plain CT scan showed hypodense. The obvious inten- sification range around large lesion was decreased after enhancement, and that around small lesion was equal density. After delaying, CT scan showed that many lesions were obviously intensified with equal or high densi- ty. MRI showed long T1 and long Tz signal, high signal on DWI and low signal on ADC map. Lesions were obviously intensified after enhancement and equal signal, and some of them were high signal. Five patients with biliary tract involvement showed that bile duct wall was unevenly thickened and obviously intensified, and bile duct had cystic or tubular dilatation, which located in the center of intrahepatic involvement lesion. Four patients were enlargement of hilar lymph node. Three patients were splenomegaly. One patient was cholecystic peripheral fluid. [Conclusion] Hepatobiliary direct involvement in children LCH is seen mainly in multisystem- ic and multifocal LCH. The lesions are distributed along portal venous system and have certain imaging charac- teristics. Imaging findings combined with clinical features is helpful for the diagnosis of the disease. Final diag- nosis depends on pathological examination.