Mucinous Breast Cancer: a Review Study of 5 Year Experience from a Hospital-Based Series of Cases

Abstract

Background: Mucinous carcinoma (also known as colloid carcinoma) is a particular type of breast cancer characterized by the presence of extracellular mucin and is linked with a more favorable prognosis than invasive breast carcinoma of no special type. Mucinous carcinoma of the breast is an uncommon form of breast tumor, often presenting as a lobulated, moderately well circumscribed mass on mammography, sonography, and MRI imaging. It accounts for 1 to 7% of all breast cancers. Pure mucinous breast carcinomas are rare and account for about 2% of all primary breast carcinomas. Metastatic disease happens at a lower rate than in other types of invasive carcinoma.

Methods: We present our 5 year experience with this particular pathology in a retrospective review study.

Results: We identified 25 patients with mixed and pure mucinous breast cancer, the tumor size varied greatly from 2 to 19 cm in diameter. A subset of mixed mucinous carcinomas (8 cases) showed neuroendocrine differentiation or other associated premalignant lessions.

Conclusion: Mucinous carcinoma of the breast is a rare entity with a favorable prognosis due to low incidence of lymph node metastases. Pure mucinous breast carcinoma has an even rare.

Keywords: breast; mucinous carcinoma; neuroendocrine differentiation.

Figure 1

T4 mucinous breast carcinoma. Note the tumoral extension to the skin and the nipple retraction.

Figure 2

"Pure" mucinous breast carcinoma – hypocellular variant. Sparce nests or individual cells floating in a large amount of mucin. H.E. obX30.

Figure 3

Mixed mucinous breast carcinoma with marked tumoral angiogenesis and vascular invasion. H.E. obX40.

Figure 4

Mucinous breast carcinoma, mixed type, with endocrine differentiation showing intense immunoreactivity to synaptophysin. IHC – Streptavidin Biotin, obX20.