Secretory Carcinoma of the Breast.

Secretory carcinoma of the breast is a rare but histologically distinct neoplasm that generally demonstrates an indolent growth pattern and a favorable prognosis. We present the mammographic, sonographic, and pathologic findings of a case of this tumor which initially presented as a palpable mass. Its appearance on breast ultrasound as a solid, well-circumscribed mass is not specific for this entity and, in fact, mimics benign entities such as fibradenoma, as well as other well-differentiated breast carcinomas.