腮腺原发良、恶性肿瘤CT表现的比较分析

Analysis on the CT findings of benign and malignant parotid tumors

背景与目的:腮腺富含脂肪组织,与周围骨骼肌肉形成天然对比,CT能够较好地评价腮腺病变及其对周围结构的侵犯情况。术前CT对腮腺良恶性肿瘤的准确判断与评估能够有效指导临床诊断与治疗。本研究探讨CT对腮腺原发良、恶性肿瘤的鉴别诊断价值,提高术前定性诊断精确性。方法:回顾性分析了经病理证实的17例腮腺原发良性肿瘤和15例恶性肿瘤的CT表现,并进行统计学处理。32例患者均行CT增强扫描。由两位资深放射科医生进行阅片分析。结果:本组良性肿瘤(14/17)多表现为圆形或类圆形肿块,而恶性肿瘤(9/15)以分叶状或不规则肿块影常见,P=0.027。良性肿瘤(6/17)常出现散在小片状低密度灶,恶性肿瘤组未见散在片状低密度灶,P=0.019。良性肿瘤(13/17)大部分边缘光滑清晰,恶性肿瘤(11/15)多表现为边缘毛糙模糊,P=0.012。个别良性肿瘤(2/17)与胸锁乳突肌分界欠清,恶性肿瘤部分(9/15)侵犯咬肌或胸锁乳突肌,P=0.008。良性肿瘤均未见肿大淋巴结及血管神经侵犯,恶性肿瘤6例(6/15)出现肿大淋巴结,4例(4/15)出现神经血管侵犯,P值分别为0.006和0.038。结论:肿块的形态、边缘、内部低密度灶分布以及与邻近咬肌及胸锁乳突肌分界情况是腮腺良恶性肿瘤的重要鉴别点,淋巴结转移及血管神经侵犯是恶性肿瘤的特异性征象。综合多指标观察分析,CT能对大多数腮腺良、恶性肿瘤做出正确诊断。

Background and purpose： Parotid gland is rich in fat and has obvious contrast with bone and musele in CT image. The preoperative examination of CT could help to evaluate the scale of tumor invasion and the relationship between tumor and normal tissues so that the proper therapy could be properly designed. The purpose of this study was to evaluate lhe roles of computer tomography（CT） in differential diagnosis of benign and malignant parntid tumors and to improve the diagnostic accuracy. Methods： CT images of 17 patients with benign parotid tumors and 15 patients with malignant parotid tumors proved by pathology were analyzed retrospectively. All patients underwent CT contrast-enhanced examination preoperatively. Images of all patients were retrospeclively reviewed by two experienced radiologists in the diagnosis of head and neck lumors. Results： 14 of 17 cases of benign tumors had round shapes and 9 of 15 cases of malignant tumors exhibited lobular or irregular masses（ P 〈0.05） ; Small sheet low density couht be seen in. six benign tumors（6/17） but none in malignant tumors（0/15） （ P 〈0.05） ; The edges of benign tumors（13/17） were clear but that of malignant lumors （11/15） were blurry（ P 〈 0.05） ; The borderline of two benign tumors（2/17） and sternocleidomastoht or masseter were nnelear but. most malignant tumors （9/15） invaded sternocleidomastoid or masseter（ P 〈0.01 ） ; None of benign tumors had increscent lymph node and the invasion of nerve and vein, six cases of fifteen malignant tumors had incresceut lymph node（ P 〈0.01）, and four eases had the invasion of nerve and vein（ P 〈 0.05）. Conclusions： The margin, shape, density and the invasion of sternoeleidomastoid or masseter of tumors are the important faetnrs fnr distinguishing benign from malignant parntid tumors. Increscent lymph node and the invasion of nerve and vein by tumor are the diagnostic features of malignant parotid tumors. CT examination can exactly evaluate most of the benign and malignant patotid tumors.