Metaplastic carcinoma of the breast. Review of 6 cases diagnosed at Hospital México, during the period 2000-2006

Abstract

Metaplasic breast cancer is a very unusual type of invasive carcinoma (less than 1% of all cases) and of high histological grade.¹ This category includes an heterogeneous group of unusual malignant entities² with a mixture of an epithelial invasive ductal component of high grade with a squamous or sarcomatoid component, that may show a variable phenotype (with production of bone or chondroid matrix or spindle cells).³

These tumors usually present parameters of aggressive behavior such as large size, high histological grade, no expression of estrogen and progesterone receptors or Her2/ neu; but clinically have similar prognosis to the usual invasive ductal carcinoma when stratified by stage.⁴

We present 6 cases of metaplasic breast cancer seen at the Hospital México between 2000 and 2006 with the purpose of establishing the clinical and morphologic variants of these tumors and their biologic behavior.

In summary our findings were consistent with those reported in the literature. This are predominantly large tumors, with high histological grade and metaplasic component usually of the squamous type, metastases to axillary lymph nodes in approximately 1/3 of the cases and no expression of hormonal receptors or Her2/neu.