Inflammatory breast cancer is a rare form of invasive breast cancer that affects the lymphatic vessels in the skin of the breast. 

Rather than forming a lump, the breast becomes red and swollen, and may appear like an infection. This is because it spreads along and blocks the lymphatic vessels, which remove fluid and other waste products from the body’s tissues to help prevent infections.  

Each year, about 1% to 5%^[9] of all breast cancers diagnosed are inflammatory breast cancer. 

Read more about inflammatory breast cancer.