体表高频超声对表皮样囊肿诊断价值

Sonographic features and differential diagnosis of epidermoid cyst with ultrasonography

目的探讨表皮样囊肿的声像图表现和高频超声在表皮样囊肿鉴别诊断中的应用价值。方法回顾分析经手术及病理证实的98个表皮样囊肿病灶的临床资料及超声声像图资料,并与皮脂腺囊肿、炎性包块、神经鞘瘤及脂肪瘤对比分析。结果 98个病灶中,术前超声正确诊断91个,超声诊断符合率为93%(91/98),误诊7个(其中误诊为皮脂腺囊肿3例,皮下炎性包块2例,神经鞘瘤1例,皮下脂肪瘤1例)。发生部位:位于全身表皮或皮下,其中以臀部、颈背部以及四肢关节周围多见。形状:肿物多呈圆形、椭圆形。肿物回声及边界:根据肿物回声特点可分为内部回声均质型(39%,38/98)、内部回声不均质型(55%,54/98)、肿物内部呈螺旋状或洋葱皮样外观的混合型(6%,6/98);肿物有完整包膜,边界清晰,后方回声增强,探头加压可形变,内部无血流信号显示。表皮样囊肿的形状、边界与皮脂腺囊肿和神经鞘瘤相比差异无统计学意义,χ~2值分别为0.21、0.21和1.53、0.00,P值分别为0.65、0.65和0.11、1.00;与皮脂腺囊肿和神经鞘瘤的后方回声比较差异有统计学意义,χ~2值分别为0.81和32.35,P值分别为0.004和0.000;表皮样囊肿的形状、边界与炎性包块相比差异有统计学意义,χ~2=42.62,P=0.00,炎性包块后方回声增强比较差异无统计学意义,χ~2=0.20,P=0.65;表皮样囊肿的形状、边界、后方回声与脂肪瘤比较差异有统计学意义,χ~2值分别为13.50、55.19、46.30,P值均为0.00。结论表皮样囊肿具有较典型的声像图表现,高频超声可以准确诊断及鉴别诊断表皮样囊肿。

Objective To investigate the ultrasonographic imaging characteristics and differential diagnosis of epidermoid cyst with high-frequency ultrasound. Methods The sonographic features and clinical data of 98 cases diagnosed as epidermoid cyst had been retrospective studied. Sonographic appearances of epidermoid cyst were compared with that of sebaceous glands, inflammatory mass, neurilemmoma, lipomas respectively. All the lesions were confirmed by surgery and approved by pathologic diagnosis. Results Among 98 lesions, 91 cases were diagnosed epidermoid cyst, the accuracy rate of diagnosis of epidermoid cyst were 93%(91/98), 7 cases were misdiagnosis. The location of lesions was found in skin or subcutaneous, which were commonly seen in hip, around the neck and back, limbs joint. The shape of lesions was round or oval. A total of 98 lesions were detected in 95 patients and the features of images could be classified into 3 types including of 39 cases of homogeneous echo pattern, 55 inhomogeneous echo pattern, 6 mixed echo pattern which had the onionskin-like appearance and hyperechogenicity around the rim. Most of all lesions were well-defined on sonograms, posterior enhancement and no color Doppler flow signals. There was statistically significant difference in shape, margin, echogenicity, vaseularity and posterior acoustic enhancement in epidermoid cyst compared with that of inflammatory mass, lipomas. There was no statistically significant difference in shape, margin in epidermoid cyst compared with that of sebaceous cyst, neurilemmoma. Conclusions There were characteristic features of epidermiod cysts in ultrasounography. The epidermoid cyst could be diagnosed and differential diagnosed exactly by sonography.