Mucinous Breast Carcinoma: Anatomo-Clinical Radiological and Therapeutic Features

摘要

Introduction: Mucinous carcinoma of the breast constitutes 1% to 4% of all breast cancers. Two different forms of presentation are distinguished: pure mucinous carcinoma and mixed mucinous carcinoma. The purpose of our work was to clarify the anatomo-clinical and radiological particularities of this rare form of breast cancer. Materials and methods: This was a retrospective study of a series of 14 cases of mucinous carcinoma of th e breast, including 8 pure mucinous carcinomas and 6 mixed mucinous carcinomas treated at the Maternity and Neonatal Center of Monastir between January 2009 and December 2017. Results: The frequency of mucinous carcinoma of the breast in our study period was 1.9%. The average of the patients was 55 years old. The average tumor size was 40 mm. Mucinous carcinoma of the breast was pure in 8 cases, mixed in 6 cases. The clinical size of pure CM was smaller than that of mixed CM (41 mm vs 45 mm) [p = 0.12]. Axillary adenopathies were found in 28.5% of patients. Mammography detected a total of 19 masses with three cases of multifocality. The average size was 27 mm, there was no significant difference between subtype sizes. Pure CMs had an oval shape in 83% of the cases with microlobulated contours in half of the cases, mixed CM rather had an irregular shape (71%) with indistinct contours (85%) (p = 0.01/p = 0.04). On ultrasound, pure CMs had a homogeneous hypoechogenic oval mass appearance with microlobulated contours enhancing ultrasound. The mixed CMs had an irregular shape of non-geometric contours and heterogeneous hypoechogenic appearance with posterior ultrasound attenuation (p = 0.06). Microcalcifications were present in 37% of pure CM and 60% of mixed CM (p = 0.13). Ganglionic invasion was noted in 28% of cases. The extension assessment was negative in all cases. The tumors were of low histological grade with predominance of SBR I and II grades. They expressed hormone receptors in 85% of cases. Overexpression of the HER2 gene was noted in only one case. Conclusion: It is important to distinguish between the two pure and mixed forms, because the therapeutic attitude and the prognosis depend on it. The pure form remains a favorable prognosis, whereas that of the mixed form matches that of infiltrating ductal carcinomas.