Clinicopathologic features of invasive metaplastic and micropapillary breast carcinoma: comparison with invasive ductal carcinoma of breast

Objectives: The aim of this study was to determine the frequency of metaplastic breast carcinoma and invasive micropapillary carcinoma in our population and also to compare the clinico-pathologic features of metaplastic breast carcinoma and invasive micropapillary carcinoma with invasive ductal carcinoma, not otherwise specified (IDC, NOS).

Results: 86.9% of the cases were identified as ductal carcinoma, NOS, while 2.2% were metaplastic and 0.76% cases were micropapillary carcinoma. Metaplastic carcinomas were found to be of higher grade as compared to IDC, NOS as 81% of metaplastic carcinoma were grade III compared to 35% IDC, NOS. 79% of metaplastic carcinoma were ER negative and 86% were PR negative, respectively as compared to ductal carcinoma NOS, which were 40% ER negative and 54% were PR. Similarly, 86.7% micropapillary cancers were ER positive and 73.3% were PR positive. Moreover, 66.7% micropapillary carcinoma showed nodal metastasis and 77.8% showed lymphovascular invasion, which was significantly higher than that of IDC, NOS micropapillary and metaplastic carcinomas accounts for less than 2 and 1% of the breast cancer burden in our population and highly correlates with poor prognosis parameters therefore, require more intensive management in our population.