Disseminated superficial actinic porokeratosis

Porokeratosis is a keratotic dermatosis which shows keratotic plaques or papular lesions, those are histologically characterized by cornoid lamella formation. It may how autosomal dominant inheritance. Disseminated superficial actinic porokeratosis (DSAP) is a type of porokeratosis which is provoked by chronic sun light exposure. Porokeratosis is a cancer prone disease which causes mainly squamous cell carcinoma and less commonly basal cell carcinoma or Bowen's disease. It has been shown that DSAP developed cutaneous carcinomas in 3.3%; on the other hand, disseminated superficial porokeratosis in 25.0%, localized type in 22.8%, and linear type in 15.9%.When the lesions of porokeratosis show inflammatory changes, rapid growth or ulcer formation, histopathological examinations should be done to detect early malignant changes. Recently a disease-associated gene was detected to localize on 12q23. 2-24.1; however, precise functions of the gene are not clear. [Skin Cancer (Japan) 2003; 18: 132-135]