Abstract:  Objective To analyze the two-dimensional ultrasound (2DUS) and color Doppler flow imaging (CDFI) characteristics of pure mucinous breast carcinoma (PMBC) and mixed mucinous breast carcinoma (MMBC). Methods The 2DUS and CDFI images of 49 patients with mucinous breast carcinoma (MBC), who were diagnosed by surgical pathology in the First Affiliated Hospital of Guangxi Medical University from January 2013 to December 2020, were retrospectively analyzed. The ultrasonic differences between PMBC and MMBC in shape, margin, echo pattern, posterior acoustic feature, calcification, blood flow grade and BI-RADS category were compared. Results Among 49 cases of MBC lesions, there were 1 case of BI-RADS category 3, 4 cases of BI-RADS category 4a, 15 cases of BI-RADS category 4b, 11 cases of BI-RADS category 4c, and 18 cases of BI-RADS category 5. The detection rate of heterogeneously mixed echoes in the PMBC group was higher than that in MMBC group (P=0.025). The detection rates of posterior echo attenuation and spiculated indistinct margin in MMBC group were higher than those in the PMBC group (P=0.008, 0.023); The proportions of blood flow grade 3 masses and BI-RADS class 5 masses in the MMBC group were higher than those in the PMBC group; the proportion of BI-RADS class 4b masses was lower than that in the PMBC group. Conclusions Compared with MMBC, PMBC is more easily benign ultrasound features. Comprehensive analysis of the margin, echo pattern, posterior features and CDFI findings can help to distinguish PMBC from MMBC, thereby improving the ultrasound diagnostic accuracy of MBC.

Key words: Mucinous breast carcinoma, Pure mucinous breast carcinoma, Mixed mucinous breast carcinoma, Ultrasonic features