腮腺基底细胞瘤的CT影像诊断及鉴别

CT Diagnosis and Differential Diagnosis of Basal Cell Adenoma in Parotid Gland

目的探讨腮腺基底细胞瘤(BCA)的CT特征及鉴别诊断。方法回顾性分析经手术病理证实的9例腮腺BCA患者的CT表现;9例均行CT平扫和增强;并与腮腺混合瘤、腺淋巴瘤及黏液表皮样癌的CT表现进行对照。结果 9例患者均为单发。CT平扫均表现为腮腺内稍高密度影,呈类圆形,境界清晰,CT值约34～53 HU;8例病灶体积较小,最大径0.92～2.74 cm,均位于腮腺浅叶;1例体积较大,最大径3.21 cm,同时累及腮腺深、浅叶;增强扫描,肿瘤实质部分呈明显强化,动脉期CT值约83～106 HU,静脉期强化不消退。CT平扫时,BCA与混合瘤、腺淋巴瘤及黏液表皮样癌的CT值无统计学差异(P>0.05);动脉期:BCA肿瘤实质部分的强化程度与腺淋巴瘤无明显差异(P>0.05),但均高于混合瘤及黏液表皮样癌(P<0.05);静脉期:BCA肿瘤实质部分的强化程度高于腮腺混合瘤、腺淋巴瘤及黏液表皮样癌(P<0.05)。结论 BCA作为一种相对少见的腮腺良性肿瘤,好发于老年女性;影像学表现为位于腮腺浅叶的单发病灶,密度不均,边缘清晰,增强扫描呈"快进慢出"表现;最终确诊须依靠病理学。

Objective To discuss CT appearances and differential diagnosis of Basal Cell Adenoma（BCA） in parotid gland.Methods CT findings of 9 patients with pathologically proved BCA were analyzed retrospectively,9 cases received plain and enhanced CT scanning,CT appearances between BCA,pleomorphic adenoma,gland lymphoma and mucoepidermoid carcinoma were compared.Results CT scan showed a solitary round or oval well circumscribed mass in all 9 cases,all lessions showed hyperdensity with CT value about 34~53 HU;8 cases was smaller and found in superficial lobe with the largest diameter from 0.92 cm to 2.74 cm,1 case involved deep and superficial lobe with the largest diameter of 3.21 cm.The tumors were markedly enhanced.There was not a statistical difference among BCA,pleomorphic adenoma,gland lymphoma and mucoepidermoid carcinoma on CT value（P0.05）;On arterial phase,the enhanced degree between basal cell adenoma and gland lymphoma had no obvious difference（P 0.05）,but were higher than that of pleomorphic adenoma and mucoepidermoid carcinoma.（P 0.05）;On venous phase,the enhanced degree of basal cell adenoma were higher than the pleomorphic adenoma,gland lymphoma and mucoepidermoid carcinoma（P 0.05）.Conclusion BCA is a rare soft tissue tumor in parotid gland,which is predominantly occurred in elder females.Imaging findings include a solitary round or oval well circumscribed mass in the superficial lobe;the lesion is significantly enhanced.However,the definite diagnosis should be depended on the histopathological and immunohistochemical results.