ABSTRACT
Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy that affects the rich in apocrine sweat glands areas. Erythema of the covered underpants area has been described as a sign of advanced stage EMPD with lymphatic infiltration. The most frequent differential diagnoses are eczema, fungal infection, psoriasis, seborrheic dermatitis, lichen sclerosus, Bowen's disease, squamous cell carcinoma, basal cell carcinoma, melanoma, mycosis fungoides, histiocytosis, hidradenitis suppurativa, or Crohn's disease. The correct diagnosis is usually delayed by an average of 2 years. Early diagnosis of EMPD is desirable for a favorable prognosis because a delayed diagnosis can result in a more extensive lesion, dermal invasion or distant metastasis. Although there are few data on the diagnostic accuracy of non-invasive dermatologic imaging techniques for EMPD lesions, it seems that dermoscopy and reflectance confocal microscopy can add relevant information that, integrated with clinical examination, may assist this challenging diagnosis and help to define surgical margins.
