Invasive Micropapillary Carcinoma of Breast: An Under-recognized Entity. A series of Eight Cases

Abstract: Invasive micropapillary carcinoma (IMPC) of breast is a morphologically distinct and relatively uncommon variant of invasive ductal carcinoma. It is characterized by small clusters of tumor cells with surrounding clear stromal spaces; a tendency for vascular permeation and therefore, an aggressive clinical course. This morphologic pattern can be easily missed especially in a small biopsy specimen because pathologists may disregard the clear spaces as artifactual. With a tendency of presenting at a higher stage, this morphological pattern needs to be mentioned in the histopathology report whenever it is encountered, either in its pure form or admixed with conventional ductal carcinoma. We describe eight cases of IMPC of breast along with their variable clinical presentations.