Etiology: Paget cells theorized to arise from an underlying ductal carcinoma, with migration of malignant cells through the ductal system of the breast and into the epidermis of the nipple

Epidemiology: Seen in 1-3% of new breast cancer cases; Peak incidence: Age 50–60; Associated with underlying ductal carcinoma (in situ and/or invasive) in 85-88% of cases

Clinical presentations: Erythematous, scaling, and/or ulcerated lesion that begins on nipple and spreads to areola. Pain, burning, or itching are early symptoms. Can present with palpable mass (50%), isolated imaging abnormality (20%), or neither (30%). Differential includes eczema (does not resolve with topical steroids) and melanoma (no changes in skin pigmentation)

Diagnosis: Punch or full-thickness wedge biopsy of the nipple; Pathology: Intraepithelial adenocarcinoma cells (Paget cells); MRI may be useful to determine extent of disease

Imaging features: Mammogram (variable): Most specific finding is asymmetric thickening of the nipple/areolar complex

Treatment: Mastectomy (or breast conserving surgery [BCS] if possible) followed by radiation therapy +/- adjuvant chemotherapy based on underlying carcinoma type. BCS an option if the nipple/areolar complex and the underlying cancer can be excised with negative margins and an acceptable cosmetic result

(Sabel 2014, Scholtz 2013)

MALIGNANT BREAST DISORDERS:

Paget Disease