Paget's disease of the breast is a disorder of the nipple-areola complex that, 
while rare, is often associated with an underlying carcinoma. It is 
characterized by eczematoid changes of the nipple. Two theories have been 
proposed to explain the pathogenesis of Paget's disease. The Epidermotropic, 
which is the most accepted theory, suggests that Paget's cells originate from 
ductal cancer cells that had migrated from the underlying breast parenchyma. It 
is supported by the predominance of breast cancer markers found in Paget's 
disease. This article provides an overview of Paget's disease of the breast with 
special attention to immunohistochemistry and raises the question of new 
therapeutic approaches.