Paget disease of the nipple presents with eczematous skin changes and is characterized histologically by large cells with clear cytoplasm within the epidermis. These intraepidermal Paget cells stain positive for:

• A S100 protein and HMB-45 (melanocytic markers)
• B CD30 and CD3 (lymphoid markers)
• C Chromogranin and synaptophysin (neuroendocrine markers)
• D CK7, CEA, and HER2 (cytokeratin and carcinoma markers) ✓

Explanation

Paget cells of the nipple are adenocarcinoma cells that migrate from an underlying ductal carcinoma in situ (DCIS) through the lactiferous ducts to invade the nipple epidermis. They express carcinoma markers: CK7, CEA, EMA, and HER2 (HER2/neu overexpression is particularly common). They are negative for melanocytic markers (distinguishing from melanoma) and lymphoid markers. Mucin stains (Alcian blue/PAS) may highlight intracellular mucin in Paget cells.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.