What is Paget's disease of the breast?

Paget's disease of the breast is a type of cancer that outwardly may have the appearance of eczema, with skin changes involving the nipple of the breast. The condition is an uncommon disease accounting for 1 to 4.3% of all breast cancers and was first described by Sir James Paget in 1874.

The condition in itself often appears innocuous, limited to a surface appearance and it is sometimes dismissed, although actually indicative of underlying breast cancer. Immunohistochemistry of Paget cells and underlying breast cancer show a more aggressive, HER2-enriched, molecular subtype of breast cancer.