RESUMEN
Mucinous micropapillary carcinoma of the breast also described as pure mucinous carcinoma with micropapillary pattern has recently come to attention as an unusual form of invasive breast cancer exhibiting dual mucinous and micropapillary diff erentiation. A 70-year-old lady presented with a complaint of a left breast palpable mass detected 4 months earlier. A fi rm well-defi ned mass of size 4 cm × 3 cm was noted with a small focal ulceration. Her past medical records and family history non-contributory. Ultrasonography revealed a well-defi ned lobulated hypoechoic lesion. Micropapillary pattern being an aggressive counterpart in pure mucinous breast carcinoma. It has increased propensity for lymph node metastasis, so it should recognized by characteristic cytological features and histological findings.