颌下腺良恶性病变的CT表现分析

目的 探讨颌下腺良恶性病变的特征性CT表现.方法 回顾性分析经手术病理证实的75例颌下腺良恶性病变的CT表现,其中多形性腺瘤38例,恶性肿瘤22例,慢性炎症11例,肌上皮瘤2例,神经鞘瘤及血管瘤各1例；总结其CT诊断及鉴别诊断要点.结果 (1)38例多形性腺瘤病灶均仅累及患侧颌下腺的一部分,其中35例位于颌下腺边缘,33例边缘光整,30例密度均匀；增强后33例病灶呈轻中度强化；10例病灶呈“靶状”强化.(2)22例恶性肿瘤中3例淋巴瘤边缘光整、密度均匀,位于颌下腺边缘,增强后呈轻中度强化；余19例边缘不光整、密度不均匀,18例边界不清楚,其中2例侵犯大部分颌下腺,16例侵犯整个颌下腺,增强后17例呈明显不均匀强化,其中12例内见增粗迂曲的血管影；9例伴有颈部短径＞1.0 cm的肿大淋巴结.(3)颌下腺慢性炎症11例,均表现为颌下腺弥漫增大,边缘较光整,边界较清楚,增强后多呈较均匀中等强化；其中6例伴有颌下腺导管内结石及导管扩张；11例均伴有颈部短径＜1.0 cm的淋巴结,其中8例短径＜0.5 cm.(4)2例肌上皮瘤具有明显不规则环形强化的CT表现；1例神经鞘瘤伴明显囊变,增强后边缘轻度强化；1例血管瘤内见多个静脉石,增强后呈明显持续强化.结论 颌下腺良恶性病变大多数具有一定的特征性CT表现,但颌下腺淋巴瘤与多形性腺瘤较难鉴别.

Analysis of CT findings of submandibular gland benign and malignant lesions

Objective To explore the characteristic CT features of benign and malignant submandibular gland lesions.Methods CT scans of 75 cases of submandibular gland lesions verified pathologically after surgery were analyzed retrospectively,including 38 cases of pleomorphic adenoma,22 cases of malignant tumors,11 cases of chronic submaxillaritis,2 cases of myoepithelioma,1 case of neurilemoma and 1 case of hemangioma.Results ( 1 ) All 38 cases of submandibular gland pleomorphic adenoma only occupied a part of submandibnlar gland.Thirty five lesions were on the edge of submandibular gland.The edge of 33 lesions were smooth and the density of 30 lesions were even.Thirty three lesions were slightly or moderately enhanced and 10 lesions showed “target sign” on enhanced CT.( 2 ) There were 22 cases of submandibular gland malignant tumors.Three lesions of lymphoma located at the edge of submandibular gland with smooth edge and even density,and showed mild to moderate enhancement.The remaining 19 lesions showed rough edge and uneven density.Eighteen of the 19 lesions showed ill-defined boundary,2 of the 18 lesions invaded most of submandibular gland and 16 of the 18 lesions invaded the whole submandibular gland.Seventeen lesions were unevenly enhanced,thickened,cirvilinear vessels were seen in 12 of the 17 lesions.Nine cases were accompanied with swollen lymph nodes ( minor diameter greater than 1.0 cm) in neck.(3)There were 11 cases of chronic submaxillaritis,which showed enlargement of the whole submandibular gland with relative smooth edge and relative clear boundary.Most of lesions were moderately and evenly enhanced.Six cases were companied with submandibular duct lithiasis and dilatation.All of 11 cases were accompanied with lymph node enlargement in neck.(4) Two cases of myoepithelioma demonstrated irregular ring enhancement on CT;one case of neurilemoma showed obvious cystic changes and slight enhancement on the edge;1 case of hemangioma showed multiple phleboliths and prolonged contrast enhancement.Conclusions Most of submandibular gland benign and malignant lesions show some degree of characteristic CT findings.It is relatively difficult to discriminate between lymphoma and submandibular gland pleomorphic adenoma.