腮腺粘液表皮样癌的CT表现分析

Analysis of CT manifestations of mucoepidermoid carcinoma in parotid gland

目的分析腮腺粘液表皮样癌(MEC)的CT表现,提高其CT诊断准确性。方法回顾性分析经手术病理证实的20例(MEC)的CT资料。20例中男7例,女13例,年龄14~71岁,中位年龄45.6岁。对肿瘤的部位、大小、形态、边界、CT密度及增强特点进行分析。结果 20例患者均为单发肿瘤,右侧8个,左侧12个,其中病灶位于腮腺浅叶11个,深叶6个,跨深、浅叶3个。肿瘤最大径约0.6~3.8cm,平均(2.0±0.2)cm;病灶呈类圆形或椭圆形肿块5例,不规则分叶状肿块15例;边缘光整8例,边缘不光整12例,其中病灶周围脂肪间隙模糊4例,局部皮肤受侵3例,下颌后静脉被包埋2例;密度均匀6例,不均匀14例(70%)。CT平扫病灶呈等密度12例,低密度8例;病灶内均未见明显钙化;增强后病灶呈明显强化13例(65%)、中度强化5例、轻度强化2例。伴颈部淋巴结肿大者3例。结论腮腺浅叶、单发、侵袭性生长、强化明显、伴有囊腔形成的肿块以及伴有明显强化的颈部肿大淋巴结可以提示MEC的诊断,CT检查可以准确显示病灶累及的范围,为临床制定治疗策略提供客观依据。

Objective To investigate the CT findings of mucoepidermoid carcinoma（ MEC） in parotid gland in order to enhance the diagnostic accuracy of this disease. Methods CT findings of 20 patients with pathologically proved MEC were retrospectively reviewed. Those 20 patients included 7 men and 13 women,with a median age of 45. 6 years old. The tumor location,size,morphology,edge,CT density,and enhancement characteristics were all analyzed in this work. Results Each of those 20 patients had only 1 tumor. Eleven lesions were located in the superficial lobe,6 lesions in the deep lobe and 3 lesions across the deep and superficial lobe. The maximum diameter of lesions ranged from 0. 6 to 3. 8 cm. Five cases were demonstrated to be round or oval round masses,fifteen cases demonstrated to be irregular masses,eight lesions showed to be well defined margin,and twelve lesions showed to be ill defined edge. Among them,the peritumoral fat tissues were blurred in 4 cases,the local preauricular skin was invaded in 3 cases and the retromandibular vein was embedded in 2 cases. The densities were homogeneous in 6 cases and unhomogeneous in 14 cases. Compared to normal muscle,12 cases manifested as isodensity and 8 cases manifested as slight low-density on CT plain scan. No lesions were shown calcification. On post contrast images,lesions were demonstrated remarkable enhancement in 13 cases,moderate enhancement in 5 cases,and slight enhancement in 2 cases. Enlarged cervical lymph nodes were found in 3 cases（ 15%）. Conclusion Infiltrative and ill defined single masses located in the superficial lobe with marked enhancement and lumen formed,accompanied with obviously enhanced cervical lymphnodes,which can indicate the diagnosis of MEC. CT examinations can accurately demonstrate the extent of tumor involvement and provide more comprehensive information for the strategy of clinic therapy.