Weindling Steven M, Wood Christopher P, Hoxworth Joseph M
1 Department of Diagnostic Radiology, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224.
2 Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN.
AJR Am J Roentgenol. 2017 Nov;209(5):1119-1127. doi: 10.2214/AJR.17.18102. Epub 2017 Aug 16.
The objective of this study is to compare the prevalence of hypoglossal canal lesions and identify differentiating imaging features.
A 15-year retrospective review of lesions of the hypoglossal nerve and hypoglossal canal, excluding those in patients with metastasis or prior head and neck cancer and those treated with radiation or surgery, was performed. Clinical findings and lesion imaging features were documented. The contrast-enhanced T1-weighted nonenhancing cystic component of hypoglossal schwannomas was compared with size-matched pathologically proven vestibular schwannomas.
Our review identified 40 lesions encroaching on the hypoglossal canal, located within the hypoglossal canal, or found in both locations: 16 hypoglossal schwannomas, 15 juxtaarticular cysts, and nine purely cystic hypoglossal canal lesions. Hypoglossal schwannomas, which were intradural when involving the premedullary cistern, most commonly enhanced heterogeneously, with a thick peripheral enhancing component, a central enhancing component, or both enhancing components. Juxtaarticular cysts encroaching on the hypoglossal canal were extradural, were contiguous with a craniocervical junction synovial joint, and showed thin rim enhancement. Hypoglossal canal nonenhancing cystic lesions were confined to the hypoglossal canal, had signal intensity equivalent to CSF, and lacked any contrast enhancement.
Although hypoglossal schwannomas, juxtaarticular cysts, and hypoglossal canal nonenhancing cystic lesions may all encroach on or lie within the hypoglossal canal, purely cystic lesions are unlikely to be schwannomas. A diagnostic algorithm applying key imaging and clinical findings allows differentiation of these lesions, which have vastly different treatment regimens.
本研究的目的是比较舌下神经管病变的患病率并确定其鉴别性影像学特征。
对舌下神经和舌下神经管病变进行了15年的回顾性研究，排除有转移或既往有头颈部癌症的患者以及接受过放疗或手术的患者。记录临床发现和病变的影像学特征。将舌下神经鞘瘤的对比增强T1加权无强化囊性成分与大小匹配的经病理证实的前庭神经鞘瘤进行比较。
我们的回顾确定了40个侵犯舌下神经管、位于舌下神经管内或在两个部位均发现的病变：16个舌下神经鞘瘤、15个关节旁囊肿和9个单纯囊性舌下神经管病变。舌下神经鞘瘤累及延髓前池时位于硬膜内，最常见的是不均匀强化，有厚的周边强化成分、中央强化成分或两者均有强化成分。侵犯舌下神经管的关节旁囊肿位于硬膜外，与颅颈交界滑膜关节相邻，表现为薄环状强化。舌下神经管无强化囊性病变局限于舌下神经管，信号强度与脑脊液相当，无任何对比增强。
虽然舌下神经鞘瘤、关节旁囊肿和舌下神经管无强化囊性病变都可能侵犯或位于舌下神经管内，但单纯囊性病变不太可能是神经鞘瘤。应用关键影像学和临床发现的诊断算法可对这些病变进行鉴别，它们的治疗方案差异很大。
