Causes

It's not clear what causes inflammatory breast cancer.

Doctors know that inflammatory breast cancer begins when a breast cell develops changes in its DNA. Most often the cell is located in one of the tubes (ducts) that carry breast milk to the nipple. But the cancer can also begin with a cell in the glandular tissue (lobules) where breast milk is produced.

A cell's DNA contains the instructions that tell a cell what to do. The changes to the DNA tell the breast cell to grow and divide rapidly. The accumulating abnormal cells infiltrate and clog the lymphatic vessels in the skin of the breast. The blockage in the lymphatic vessels causes red, swollen and dimpled skin — a classic sign of inflammatory breast cancer.