Ginat D T, Vargas S O, Silvera V M, Volk M S, Degar B A, Robson C D
From the Departments of Radiology (D.T.G., V.M.S., C.D.R.).
Pathology (S.O.V.) Harvard Medical School (S.O.V., V.M.S., M.S.V., B.A.D., C.D.R.), Boston, Massachusetts.
AJNR Am J Neuroradiol. 2016 May;37(5):910-6. doi: 10.3174/ajnr.A4644. Epub 2016 Jan 7.
Juvenile xanthogranuloma is a non-Langerhans cell histiocytosis primarily affecting children. The purpose of this study was to characterize the imaging features of histologically confirmed pediatric head and neck juvenile xanthogranuloma.
A retrospective review was performed of medical records and imaging of histologically confirmed head and neck juvenile xanthogranuloma.
Ten patients (6 girls, 4 boys) 1 month to 12 years of age were imaged with ultrasound only (n = 1), CT only (n = 2), CT and ultrasound (n = 1), MR imaging only (n = 3), or MR imaging and CT (n = 3). Masses were solitary in 9 patients and multiple in 1. Solitary masses were located in the external auditory canal, infra-auricular region, infratemporal fossa with intracranial extension, frontal scalp, and subperiosteal space eroding the calvaria and along the dura. One patient with disseminated disease had scalp-, calvarial-, and dural-based masses. Clinical presentation included a mass or alteration in function. On sonography, juvenile xanthogranuloma appeared hypoechoic. On contrast-enhanced CT, masses appeared homogeneous and isoattenuating with muscle and sometimes eroded bone. On MR imaging, compared with the cerebral cortex, the masses appeared hyper- or isointense on T1 and hypo- or isointense on T2, had decreased diffusivity, and enhanced homogeneously. Juvenile xanthogranuloma was not included in the differential diagnosis in any case.
Head and neck juvenile xanthogranuloma has varied manifestations. Mild hyperintensity on T1, hypointensity on T2 compared with the cerebral cortex, decreased diffusivity, and homogeneous enhancement are characteristic. Awareness of these features should prompt radiologists to include juvenile xanthogranuloma in the differential diagnosis of pediatric head and neck masses.
幼年性黄色肉芽肿是一种主要累及儿童的非朗格汉斯细胞组织细胞增多症。本研究的目的是描述经组织学证实的儿童头颈部幼年性黄色肉芽肿的影像学特征。
对经组织学证实的头颈部幼年性黄色肉芽肿的病历和影像学资料进行回顾性分析。
10例患者（6例女孩，4例男孩），年龄1个月至12岁，仅行超声检查（n = 1）、仅行CT检查（n = 2）、CT和超声检查（n = 1）、仅行磁共振成像（MR成像）检查（n = 3）或MR成像和CT检查（n = 3）。9例患者为单发肿块，1例为多发肿块。单发肿块位于外耳道、耳下区域、颞下窝伴颅内延伸、额部头皮以及侵蚀颅骨和沿硬脑膜的骨膜下间隙。1例播散性疾病患者有头皮、颅骨和硬脑膜肿块。临床表现包括肿块或功能改变。超声检查时，幼年性黄色肉芽肿表现为低回声。增强CT上，肿块表现均匀，与肌肉等密度，有时侵蚀骨质。MR成像上，与脑皮质相比，肿块在T1加权像上呈高信号或等信号，在T2加权像上呈低信号或等信号，扩散受限，且均匀强化。所有病例的鉴别诊断中均未考虑幼年性黄色肉芽肿。
头颈部幼年性黄色肉芽肿有多种表现形式。与脑皮质相比，T1加权像轻度高信号、T2加权像低信号、扩散受限和均匀强化是其特征。了解这些特征应促使放射科医生在儿童头颈部肿块的鉴别诊断中考虑幼年性黄色肉芽肿。
