Paget Disease of the Breast in Pregnancy and Lactation.

Paget's disease of the breast (PDB) is a rare breast carcinoma believed to arise from an underlying in situ or invasive ductal cancer that migrates through the epidermis causing characteristic skin changes including scaling, redness, and itching of the nipple, areola, and sometimes the surrounding skin. Although Paget's may mimic benign conditions such as contact or allergic eczema and mastitis, it should remain a strong consideration in the differential diagnosis , especially in peripartum women for whom benign conditions such as bacterial mastitis from breastfeeding are common. The workup of Paget's should focus on both making the diagnosis with nipple/skin scrape cytology or punch biopsy as well as evaluating any underlying mass with mammogram, breast ultrasound , and also a core needle biopsy , if required. Treatment focuses on management of the underlying breast cancer as usual. The purpose of this chapter is to describe the presentation of PDB as well as outline an approach to its diagnosis and management, especially in the setting of pregnancy and lactation.