Paget disease of the nipple is characterized histologically by the presence of large, pale, vacuolated malignant cells within the epidermis of the nipple. These cells originate from:

• A Melanocytes of the nipple areolar complex undergoing malignant transformation
• B Underlying ductal carcinoma in situ (DCIS) or invasive ductal carcinoma spreading intraepidermally ✓
• C Toker cells, a normal component of nipple epidermis undergoing malignant change
• D Paget cells derived from Merkel cells in the nipple epithelium

Explanation

Paget disease of the nipple results from intraepidermal migration of adenocarcinoma cells from an underlying breast ductal carcinoma (DCIS or invasive), not from de novo epidermal malignancy. The Paget cells are large, pale, HER2/ErbB2-positive cells within the squamous epidermis, which they access via direct spread along the epidermotropic route. The presentation mimics eczema or dermatitis of the nipple. An underlying breast mass or DCIS is present in >95% of cases. Toker cells are normal clear cells in nipple epithelium but do not give rise to Paget disease.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.