肉芽肿性乳腺炎的MR表现特征及其误诊原因分析

MRI Features of Granulomatous Mastitis and Analysis of its Misdiagnosis

目的分析肉芽肿性乳腺炎(GM)的MR表现特征及误诊原因,以期提高其诊断准确率。方法选取粤北人民医院经病理证实的23例GM患者的MR资料。结果 23例均为女性,年龄25~47岁,平均年龄34.9岁。均为单侧乳腺发病,其中位于左侧者13例(56%)。15例表现为非肿块型(65%),另外8例为肿块型。14例局限在一个象限(60%),9例累及多个象限。16例见单发或多发小脓腔,囊壁厚、部分内见条状或线样分隔,DWI呈明显高亮信号,ADC低信号,增强后呈蜂窝状、环状边缘强化。动态增强12例脓腔周围炎性反应呈现渐进性强化特点。5例表现为实性肿块(1例呈分叶状),增强呈明显均匀强化。间接征象包括周围皮肤出现水肿14例,Cooper韧带逐渐增厚7例,3例严重者皮下出现小脓肿。TIC曲线主要为Ⅰ型(14例,占60%)或Ⅱ型(6例,占26%),有3例为Ⅲ型(误诊为乳腺癌)。在ADC图上测得平均ADC值为(1.167±0.136)mm^2/s。结论 GM的临床及影像表现具有一定的特征,结合动态强化及TIC曲线特点,以及对DWI信号及ADC值综合分析,可以明显提高对该病的诊断准确率。

Objective To analyze the MR manifestations and misdiagnosis causes of granulomatous mastitis（ GM）,and improve accuracy of GM diagnosis. Methods 23 patients with MR data confirmed as GM by pathology in the hospital were selected. Results All cases were female,aged 25 ～ 47 years,with an average age of 34. 9 years. All cases were unilateral breast lesions,of which13 cases were located on the left side（ 56%）. 15 patients showed a non-tumor type（ 65%） and 8 patients had a mass type. 14 cases were located to one quadrant（ 60%）,and 9 cases involved multiple quadrants. Single or multiple small abscesses were found in 16 patients,with the cystic wall thickness and partial in-strip-like or line-like separation. The presence of abscesses was determined by a hyperintense signal on DWI and hypointense signal on ADC. After gadolinium administration,honeycomb and ring edge enhancement were showed. Dynamic enhancement of peri-injury inflammatory response showed progressive enhancement in 12 cases. In 5 cases,solid masses（ one lobulated） presented and the enhancement was markedly uniform. Indirect signs was found as follow： 14 cases with edema around the skin,7 cases with thickening of Cooper ligament,and 3 cases with small abscesses under the skin. The TIC curve was mainly type I（ 14 cases,60%） or type II（ 6 cases,26%）,and 3 cases were type III（ which misdiagnosed as breast cancer）. The average ADC value measured on the ADC plot was（ 1. 167 ± 0. 136） mm^2/s. Conclusion GM has some clinical and imaging characteristics. Comprehensive analysis of DWI signals,ADC values,dynamic enhancement and TIC curve features,the diagnostic accuracy of GM can be significantly improved.