腮腺Warthin’s瘤的MRI表现

MRI diagnosis of Warthin's tumor

目的探讨腮腺Warthin’s瘤的MRI特征,提高MRI对腮腺Warthin’s瘤的诊断率。方法回顾性分析本院2005年8月～2012年5月期间经手术及病理证实的有完整MRI影像学资料的13例腮腺Warthin’s瘤患者共17个病灶的MRI影像学特征。13例患者中男性12例,女性1例,年龄38～82岁,中位年龄59岁。结果 13例患者中9例为单发病灶(9个病灶),4例为双侧病灶(8个病灶)。17个病灶中,位于浅叶者14个,其中13个位于腮腺后下极者,同时累及浅叶深叶者3个,无单独发生于深叶的病灶;病灶直径1～4cm,平均2.25cm;16个病灶边界清楚,2个病灶有分叶、呈结节状,1个病灶边界欠清,病理证实为炎症浸润;16个病灶个病灶包膜完整,1个病灶因炎症浸润包膜显示不完整;与肌肉信号比较,T1WI病灶呈等低信号,压脂T2WI表现为明显高信号,其中3个病灶信号均匀,其余14个病灶内因含囊性区而信号明显不均匀;17个病灶内均未见钙化灶。增强后扫描,17个病灶均有明显强化,其中14个病灶内囊性区无强化,实质成分明显强化,其余3个病灶呈均匀强化;17个病灶均出现对比剂注射后2min明显强化,4～5.5min后肿瘤信号明显减低。结论腮腺Warthin’s瘤具有其特征性MRI影像学表现,如果长期吸烟史的中老年男性患者,腮腺出现长T1、长T2边界清楚的圆形或卵圆形、包膜完整的占位灶,瘤灶内出现囊变区,增强后扫描病灶早期强化明显,无延迟强化特征,特别是当出现双侧腮腺发病或一侧腮腺多发占位灶时,应首先考虑到Warthin’s瘤的可能。

[Abstract] Objective To explore MR imaging features of Warthin＇s tumor in parotid gland, and to improve MRI diag- nostic accuracy. Methods 17 tumors in 13 patients （12 males and 1 female, aged from 38-82 years, mean 59 years） were scanned by MR imaging system from Aug 2005 to May 2012. The histopathologic diagnosis was performed after surgical resection. MR findings were compared with pathologic analysis. Results In these 13 patients, nine patients had unique tumor, while the other four had bilateral tumors. 14 tumors were located in the superficial lobe, and 13 were located in the caudal portion of the parotid gland, while the other 3 tumors involved both superficial and deep lobes. The average maxi- mal cross-sectional diameter was 2.25 cm （range, 1-4 cm）. 16 tumors showed well-defined margins, and the other one showed ill-defined, which was confirmed inflammatory infiltration by pathology. Compared with muscle signal, all of the tumors showed hypo-signal in Tl-weighted imaging and hyper-signal in FS Tz-weighted imaging. Three tumors were hom- ogeneous signal masses, while the other 14 showed heterogeneous signal, with cystic region in them. Contrast-enhanced MR images showed obviously contrast within 2 min and significant washout within 4-5.5 min in all tumors. Conclusion The parotid Warthin＇s tumors were demonstrated characterized findings in MR imaging. Generally, masses were well-de- fined, with hypo-signal in Ta-weighted imagings and hyper-signal in fat saturation T2-weighted imaging, especially in older men with long-term smoking history and bilateral or multiple in unilateral involved. Contrast-enhanced MR images showed obviously contrast within 2 min and significant washout within 4-5.5 min.