乳腺原发性腺样囊性癌的影像学表现

Imaging features of primary adenoid cystic carcinoma of the breast

目的:探讨乳腺原发性腺样囊性癌(adenoid cystic carcinoma,ACC)的影像学表现特征,提高对该病的认识和诊断准确性。方法:回顾性分析2012年1月至2018年9月天津医科大学肿瘤医院31例经病理证实的乳腺原发性ACC患者的临床资料,根据乳腺影像报告与数据系统(breast imaging reporting and data system,BI-RADS)标准分析其X线和超声表现,并与病理进行对照。结果:31例乳腺原发性ACC患者的乳腺X线表现为肿物25例和局限不对称致密6例,所有病变均无钙化。25例患者中高或稍高密度肿物16例、等密度肿物7例和混杂密度肿物2例。31例患者的乳腺超声检查表现为肿物25例和非肿块样病变6例。25例患者中22例为低回声肿物和3例为混合回声肿物;6例非肿块样病变患者包括低回声区和偏高回声为主的混合回声区各3例,均无沿导管走行方向分布的趋势。结论:乳腺原发性ACC的影像学表现无特异性,但乳腺X线表现形态不规则且边缘模糊的高密度肿物内含稍低密度或脂肪样密度区域,乳腺超声表现偏高回声为主且不沿导管走行方向分布的非肿块样病变等征象具有一定提示意义,最终确诊依靠病理。

Objective: To investigate the imaging features of primary adenoid cystic carcinoma(ACC) of the breast. Methods: In total, 31 patients were confirmed to have primary ACC in the breast based on histopathological findings from January 2012 to September 2018 in Tianjin Medical University Cancer Institute and Hospital. Mammography and ultrasonography findings of these patients were retrospectively analyzed according to the breast imaging-reporting and data system(BI-RADS) recommended by the American College of Radiology(ACR)and compared with pathological findings. Results: Mammography findings in 31 cases of ACC of the breast were as follows: 25 cases with masses, including 16 high-density masses(14 were categorized as BI-RADS 4 C or 5, one as 4 A, and one as 4 B);7 equal-density masses(5 were categorized as BI-RADS 4 B, one as 4 A,and one as 3);and 2 mixed-density masses(one was categorized as BI-RADS 4 A and one as 2).The other 6 patients presented with focal asymmetric density. No calcification was found in all cases. Ultrasonography findings included hypoechoic mass, mixed-echo mass, and non-mass-like hypoechoic or heterogeneous echoic areas. A total of 22 patients presented with hypoechoic masses;of these, 14 showed typical ultrasonographic findings of breast cancer and their tumors were categorized as BI-RADS4 C or 5. Three patients presented with mixed-echo masses, of which two showed a mixed-echo mass containing hyper-echoic areas and one showed a complex cystic and solid echo mass;all tumors were categorized as BI-RADS 4 B. The remaining 6 patients presented with non-mass-like hypoechoic or heterogeneous echoic areas;all were without a tendency to distribute along the direction of the breast ducts.Conclusions: The mammographic and ultrasonographic appearances of primary ACC of the breast are similar to those of general carcinoma,with no specificity. Some specific findings, such as irregular high-density masses containing low-or fatty-density areas with indistinct margins on mammography and mixed-echo masses containing hyper-echo or non-mass-like heterogeneous echoic areas not distributed along the breast duct on ultrasonography, have certain significance. The final diagnosis depends on histopathology.