What is extramammary paget disease?

➢ Paget disease is an Intraepidermal proliferation of epithelial cells that can occur in the skin of the vulva or nipple of the breast. ➢ Only a minority of cases of vulvar (extramammary) Paget disease have an underlying tumor. ➢ Manifests as a red, scaly, crusted plaque that may mimic the appearance of an inflammatory dermatitis. ➢ Histo : • large cells with abundant pale, finely granular cytoplasm • Occasional cytoplasmic vacuoles (DD with melanoma; PAS+++) • Infiltrate the epidermis, singly and in groups ➢ May persist for years or even decades without evidence of invasion. ➢ However, when there is an associated tumor involving skin appendages, the Paget cells may invade locally and ultimately metastasize. ➢ After metastasis occurs, the prognosis is poor