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

PURPOSE

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.

MATERIALS AND METHODS

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

RESULTS

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.

CONCLUSION

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

Mucinous carcinoma of the thyroid: A case report and review of the literature

We report the case of a primary mucinous carcinoma of the thyroid in a man of 74 who had a 4-cm nodule in the right lobe of the thyroid, with a solido-cystic appearance on ultrasound associated with lymph node metastases. On scintigraphy, the nodule was hot and not extinctive. The patient underwent total thyroidectomy with a ipsilateral right lymph node dissection. The immunohistochemical study showed the negativity of CK 7 and CK 20 and the positivity of thyroglobulin and TTF 1. Postoperatively the rate of blood thyroglobulin 3 months after surgery had collapsed to 0.17ng/ml. The evolution was marked by the appearance of pulmonary metastasis and the patient died 4 months after surgery. Histological study showed the presence of almas of neoplastic cells surrounded by large deposits of extracellular mucin. Primitive mucinous carcinoma of the thyroid is a rare tumor which differential diagnosis is established on the positive immunohistochemistry of thyroglobulin and TTF1 but negative for other markers.