Paget disease of the nipple is characterized histologically by large cells with pale cytoplasm within the epidermis. Which statement about its pathogenesis is correct?

• A It is always associated with an underlying invasive breast carcinoma within the nipple areola
• B It represents a primary squamous cell carcinoma in situ of the nipple epidermis
• C Paget cells are activated myoepithelial cells entrapped within the epidermis
• D Paget cells are neoplastic ductal cells that have migrated epidermotropically from an underlying DCIS or invasive carcinoma ✓

Explanation

Paget disease of the nipple represents intraepidermal spread of malignant adenocarcinoma cells (Paget cells — large cells with pale cytoplasm, prominent nucleoli, and HER2 overexpression) that have migrated from an underlying ductal carcinoma (DCIS or invasive). They extend along the ductal system and into the overlying epidermis (epidermotropism). The associated underlying carcinoma can be DCIS alone (without invasion) in ~30-50%. Clinically it mimics eczema. Paget cells are not squamous in origin nor myoepithelial.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.