腮腺原发性良、恶性肿瘤的CT表现

CT Findings of Primary Benign and Malignant Parotid Tumors

目的通过对原发性腮腺良、恶性肿瘤的CT征象的分析,以提高CT对腮腺肿瘤的诊断正确率。方法分析经病理证实的54例69个病灶的CT表现,并进行统计学分析。结果良性肿瘤36例(50个),恶性肿瘤18例(19个)。73%(36/49)良性肿瘤位于浅叶,26%(13/49)位于深叶及跨叶;47%(9/19)恶性肿瘤位于浅叶,53%(10/19)位于深叶及跨叶(p=0.041)。90%(45/50)良性肿瘤边界清楚,68%(34/50)形态规则;90%(17/19)恶性肿瘤边界不清楚,84%(16/19)形态不规则(p值均为0.000)。64%(32/50)良性肿瘤密度不均匀,84%(16/19)恶性肿瘤密度不均匀。密度不均匀良性肿瘤低密度区边界清楚88%(30/34),小片状61%(21/39),恶性肿瘤低密度区边界不清100%(16/16),大片状69%(11/16)(p=0.000)。强化程度大于等于肌肉者,良性占95%(41/43),恶性占88%(16/18)。16例肿瘤可见颈部肿大淋巴结(最大横径≥8mm),8例良性,8例恶性。12例恶性肿瘤侵犯周围组织。结论位于浅叶、边界清楚、形态规则、病变内低密度区边界清楚为良性肿瘤的特点,反之则为恶性肿瘤的特点。根据患者性别、年龄及病变部位、多发性、强化特点、血管通过环绕征等,有助于多形性腺瘤与warthin’s瘤的鉴别。

Objective To analyze the CT features of benign and malignant parotid tumors and to improve the diagnostic accuracy. Methods CT images of 54 patients with 69 lesions, all of which had pathological diagnosis, were analyzed retrospectively. Results 36 cases （50 lesions） were benign tumors and 19 cases（19 lesions） were malignant. 73% （36/49） benign lesions and 47% （9/19）malignant lesions were located in the superficial lobe, whereas 26% （13/49）benign and 53% （10/19）malignant tumors were located in the deep lobe （p=0.041）. Of benign tumors, 90% （45/50） had sharp margins and 68% （34/50） were regular. While for malignant tumors, 90% （17/19） had poorlydefined margins and 84% （16/19） were irregular （both p=0.000）. 64% （32/50） benign and 84% （16/19）malignant tumors appeared heterogeneous, 88% （30/34） of the former with well defined low-density areas, but none of the latter（p=0.000）. 61%（21/39） benign lesions manifested small patchy low-density areas, and 69%（11/16）malignant lesions had large areas of low density. Enhancement level of 95%（41/ 43） benign and 88%（16/18）malignant tumors were more than the muscle＇s. 16 cases showed cervical enlarged lymph nodes（d ≥ 8mm）, of which 8 cases were malignant and 8 were benign. 12 malignant tumors infiltrated into the adjacent structures. Conclusion A well-circumscribed parotid tumor located in the superficial lobe, with regular shape and sharply defined lowdensity areas, might be benign tumor. Many factors are helpful for the differential diagnosis between Warthin＇s tumors and pleomorphic adenomas, including gender and age, location, multiple lesions, enhancement features and small penetrating or encircling vessels.