Abstract
Photodynamic diagnosis (PDD) is a non-invasive method to diagnose the possibility of cancer (or precancer). In dermatology, ALA (5-aminolevulinic acid)-induced protoporphyrin IX (PpIX) is used for PDD as well as for photodynamic therapy (PDT). The fluorescence of induced porphyrins is effective in detecting and delineating neoplastic skin areas, especially in patients with multiple lesions of actinic keratosis. However, in some patients with extramammary Paget's disease on extragenital areas or with squamous cell carcinoma on the earlobe, the detection of the area using PDD was not always compatible with the histopathological investigation. In the extragenital areas or the earlobe, the area determined by PDD may not be accurate.[Skin Cancer (Japan) 2009 ; 24 : 450-454]
