Disseminated superficial actinic porokeratosis, Bowen's disease and basal cell carcinoma. Coincidence or rare double malignant transformation?

Disseminated superficial actinic porokeratosis (DSAP) is a skin condition that consist of multiple annular, hyperkeratotic lesions. They are usually distributed bilaterally and mostly affect the extremities. DSAPs have a wider distribution than the porokeratosis of Mibelli and usually appears between the age of 40 and 50. Squamous cell carcinoma, Bowen’s disease, and basal cell carcinoma that arises in the classical type of porokeratosis of Mibelli is well-documented, but there are not many reported cases of Bowen’s disease and basal cell carcinoma arising in DSAP. We present a 77-year-old woman in whom the two– Bowen’s disease and Basal cell carcinoma develop in a histologically proven DSAP.