[Mucinous carcinoma of the breast: Clinical, biological and evolutive profile]

Mucinous carcinoma of the breast accounts for 1 to 4% of all breast cancer. There are two histological subtypes: mixed mucinous carcinoma, where the ductal carcinoma is associated with the colloid component, and pure mucinous carcinoma, with a favorable prognosis, where the mucus surrounds the tumour tissue and constitutes a mechanical barrier limiting cell invasion and making this form less aggressive. Our study aimed to determine retrospectively the main epidemiological, clinical, biological, and therapeutic features, as well as the prognosis of this rare form of breast carcinoma.

The authors report 32 cases of mucinous carcinoma of the breast diagnosed in Mohammed-VI centre for cancer treatment in Casablanca.

The average tumour size was 4.5cm (0.5-7cm). We found ten positive lymph node dissections, seven of them were of mixed mucinous carcinoma with a tumour size ranging between 4 and 7cm. Mucinous carcinoma was pure in 16 cases, mixed in 14 and a neuroendocrine differentiation was found in two cases. Most tumours were of an intermediate histological grade (n=19) with positive hormonal receptors (68%). After a mean follow-up of 30 months, complete remission was maintained in 92% of evaluable patients.

Mucinous carcinoma is a rare type of breast cancer, with a favourable prognosis for the pure form.