To analyze the ultrasonographic features and causes of misdiagnosis of mucinous carcinoma of breast and improve the accuracy of ultrasound diagnosis.

The sonographic appearances and pathological features of mucinous carcinoma of breast in 58 patients(a total of 60 lesions, 36 lesions of 36 cases were pure type, 24 lesions of 22 cases were mixed type) diagnosed by operation and pathology were analyzed retrospectively. Ultrasonic appeareuce such as lump quantity, size, boundary, shape, internal echo, rear echo, lump internal micro calcification or not, lump internal blood stream situation and oxter lymph nodes infiltration information were analyzed.

Among the 58 cases with mucinous carcinoma of breast, 44 cases′ preoperative ultrasonic diagnosis accorded with postoperative pathological diagnosis, ultrasonic diagnostic accuracy was 75.9%(44/58). Nine cases of pure type mucinous carcinoma were graded BI-RADS 2-3 by preoperative ultrasound, in which one case was misdiagnosed as lipoma, two cases were misdiagnosed as cyst, five cases were misdiagnosed as fibroadenoma or adenosis, one case was misdiagnosed as intraductal papilloma. In addition, five cases of mixed type mucinous carcinoma of breast were graded BI-RADS 5 by preoperative ultrasound and were misdiagnosed as imbibition ductal carcinoma.

Ultrasonography has higher diagnostic accuracy in mucinous carcinoma of breast. Pure type mucinous carcinoma of breast possess several characteristics of benign breast lumps, which should be distinguished from it. Mixed type mucinous carcinoma of breast has part sonographic characteristics of invasive ductal carcinoma, more attention should be paid to differentiate them.