Breast carcinoma with micropapillary features: clinicopathologic study and long-term follow-up of 100 cases.

To study the clinicopathologic characteristics and prognosis of invasive micropapillary carcinoma of breast (IMPC), 100 cases of invasive breast carcinoma with an IMPC component were reviewed. Compared with invasive ductal carcinoma, not otherwise specified, with similar histologic grades, carcinomas with IMPC were larger sized, had a higher lymph node metastasis rate with more nodes involved per case, and exhibited increased lymphovascular invasion. The presence of IMPC strongly correlated with the more aggressive behavior. No significant association was established between the proportion of the IMPC component and overall tumor size, histologic grade, lymph node metastasis rate, and distant metastasis, but a trend was noted. Long-term follow-up demonstrated a poorer 5-year and 10-year survival rate for patients with breast carcinoma containing an IMPC component. Breast carcinomas with micropapillary features are more aggressive tumors with a poorer prognosis. This specific structure should be carefully evaluated in the surgical pathology examination of breast carcinoma specimens.