Extramammary Paget’s Disease Histology
Histologically, Paget’s disease resembles Bowen’s disease and superficial spreading melanoma. Paget’s cells are mucin positive, as determined by Hale’s colloidal iron stain. The cytoplasm is often PAS-positive and stains with alcian blue at pH 2.5. Immunoperoxidase stains are helpful in establishing the diagnosis and in excluding conditions that resemble Paget’s disease. Most cases are CEA positive.
CEA is a sweat gland marker. Antikeratin stains Bowen’s disease and anti-S-100 protein stain is positive in melanoma. Biopsy often reveals cells that are exterior to the clinically apparent areas, a fact that explains the high rate of recurrence after excision.