We report cytologic features of a pure form of invasive micropapillary carcinoma (IMPC) of the breast in a 66-year-old woman.
Aspiration cytology of IMPC from resected specimens showed numerous cohesive clusters with an inverted growth pattern and microvilli at the periphery. The lesion resembled a group of islands. Because IMPC has a high potential for lymphatic vessel invasion an awareness of possible IMPC and definite diagnosis before mastectomy are important in disease management.
