腮腺基底细胞腺瘤的CT和MRI特点

目的 探讨腮腺基底细胞腺瘤的CT和MRI表现特点.方法 回顾性分析经手术病理证实的9例腮腺基底细胞腺瘤的CT和MRI的影像特点(6例CT检查,3例MR检查).9例中男4例,女5例,中位年龄58岁(40～79岁).对肿瘤的部位、大小、形态、边缘、CT密度或MRI信号及强化形式进行分析.结果 9例患者均为单发肿瘤,8例位于腮腺浅叶,1例位于腮腺深叶.9个肿瘤中7个为类圆形,无分叶;2个为长椭圆形,有浅分叶.9个肿瘤边缘均光滑清楚;MR检查3例,2个肿瘤周边见T2wI低信号的包膜,1个肿瘤周边见一较薄的T2WI高信号环.3个肿瘤MRI均表现为长T1、短T2信号,增强后呈不均匀轻、中度强化,内见裂隙样、小片状低信号,并出现延迟强化,1例见壁结节;CT检查6例,平扫肿瘤均表现为低密度,其中4个肿瘤CT强化共同特点均为薄壁环形强化,且有大小不等的壁结节,肇结节呈中～重度强化(平均CT值增加为65.5 HU),另外2个呈均匀中度强化.结论 老年女性患者腮腺浅叶内单发边界清楚病灶,CT增强表现为薄壁环形强化且有壁结节,MRI表现为长T1、短T2信号,强化内见裂隙样、小片状低信号且出现延迟强化,要考虑基底细胞腺瘤的可能.

Basal cell adenomas of the parotid gland: CT and MRI features

Objective To investigate the CT and MR] features of basal cell adenoma of the parotid gland. Methods CT and MRI features of 9 basal cell adenoma cases (4 men and 5 women, median age 58) confirmed by operation and pathology were reviewed retrospectively. All CT and MR images were retrospectively evaluated with respect to location, size, morphology, margin, CT density/MR] signal intensity and enhancement behavior. Results Each of the 9 patients had only 1 tumor. Eight lesions were located in the superficial lobe and 1 in the deep lobe. Seven tumors were round without lobular appearance, and 2 tumors were elliptic with small lobular appearance. All the 9 lesions were well circumscribed with smooth contours. A capsule-like rim with low intensity on MR was observed in 2 lesions, and a rim with high intensity on T1 WI and T2 WI was detected in another lesion. These 3 lesions showed low intensity on T1 WI and T2 WI with heterogeneously strong enhancement and delayed enhancement. Four lesions showed cystic areas in the center with mural nodules on CT, which were moderately or obviously enhanced (the mean increase of CT values: 65.5 H U ), and 2 lesions showed homogeneous enhancement. Conclusion Basal cell adenoma of parotid gland should be first considered when the old women had single round lesion located in the superficial lobe with smooth contour and low intensity on T2WI, especially when cystic areas were observed in the center with mural nodules on CT/MR.