儿童颞骨朗格汉斯组织细胞增生症与神经母细胞瘤转移影像鉴别价值研究

Imaging differentiation diagnosis between LCH and NB metastasis of temporal bone in children

目的探讨儿童颞骨LCH与NB骨转移的发生部位及影像学表现。方法回顾性分析经病理证实的儿童LCH及NB骨转移的临床及影像学资料,按照病变中心位置评估病变部位(中耳、鳞部、岩部),在CT及MR图像上评估病变影像学表现。结果共纳入21例(28耳)LCH患儿,乳突是最常见的累及部位(23例,82.1%),其次为鳞部和岩部。颞骨HRCT表现为较为完全的骨质破坏伴软组织肿块,边界清晰锐利,无骨膜反应,无钙化。除1例有T_1W高信号外,其余MR均表现为T_1W等低信号,T_2W等高信号,增强后明显均匀强化。共纳入NB骨转移10例,8例位于颞骨眶突移行处,2例位于颞骨鳞部。CT表现为边界欠清楚的骨质破坏伴放射状骨膜反应,软组织肿块表现为密度较均匀的略高密度,颅板骨质破坏不彻底,颅板变薄,但骨质仍连续。结论儿童LCH多累及颞骨乳中耳,NB骨转移多位于颞骨眶突移行处及鳞部。二者骨质破坏方式亦有不同,发病部位及影像学检查对于鉴别二者有重要价值。

Objective We aimed to find the difference between LCH and NB metastasis of temporal bone in pediatric patients and analyze the anatomic location and imaging findings of them. Methods We retrospectively analyzed the clinical and imaging features of LCH and NB metastasis of pediatric temporal bone. The temporal bone was divided into three subsites including middle ear, squamas and petrous apex. The accurate location and imaging features of the two pathological types were summarized on CT and MR images. Results Twenty-one LCH (seven bilateral involvement) and ten NB metastasis of pediatric temporal bone were identified. Middle ear was the most commonly involved region (82.1%, 23/28) followed by squama (78.9%, 22/28) and petrous apex (14.3%, 4/28). On CT images, LCH appeared as well-defined bony destruction with varied range of temporal bone. On MR imaging,it manifested as isointensity both on T 1 and T 2 weighted images and hypointensity on DWI. It showed homogeneous and avid enhancement after introducing contrast material. The study enrolled ten cases with metastatic NB. Eight lesions located in the lateral orbital wall and extended to squamous part of temporal bone. The other two lesions only involved temporal squama. The main imaging features were vermiform destruction with vertical spiculated periosteal reaction. The masses showed iso-intensity on T 1WI and T 2WI and obvious enhancement after administration of contrast. Conclusion The most common involved subsite of LCH is middle ear. And it manifested as well-defined and complete bony destruction of temporal bone. Metastatic NB often involved lateral orbital wall and extended to squamous part of temporal bone. On imaging examination, it shows incomplete bony destruction with vertical spiculated periosteal reaction. Combined with the help of location and imaging findings, the differential diagnosis can be made in most cases.