Micropapillary Carcinoma of Breast
Micropapillary carcinoma (MPC) of breast is an aggressive variant of ductal carcinoma that resembles micropapillary carcinomas of other primary sites such as ovary, lung, pancreas, and bladder. Pure MPC is rare and makes up between 1.5-2.5% of all breast cancers.
It usually presents as a palpable mass in the upper outer quadrant of the breast. Mammogram shows a high density irregular mass with spiculated margins. Microcalcifications are usually present. The size range is few millimeters to several centimeters and is generally larger than ductal carcinoma, NOS. Metastases to multiple axillary lymph nodes are frequently present.
The tumor cells are arranged in micropapillary, tubulo-alveolar, or morular clusters that are surrounded by lacunae or clear space.