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.