What finding is most consistent with Paget's disease of the breast?

Paget's disease of the breast is characterized by specific dermatological changes that primarily affect the nipple and areola. The most notable finding associated with this condition is a rash on the areola, which typically presents as eczema-like changes. This rash can be crusty or scaly and is often accompanied by itching or burning sensations. The development of this rash is due to underlying ductal carcinoma, frequently intraductal carcinoma, that extends to the nipple area, leading to the described changes in the skin.

The presence of a rash on the areola is a hallmark sign of Paget's disease, making it the most consistent finding associated with this condition. It is essential to differentiate this rash from other cutaneous conditions affecting the breast, as its presence warrants further investigation into possible underlying malignancies.