Basal cell carcinomata in port wine stains

The development of basal cell carcinoma (BCC) in a port wine stain is rare and the aetiology of these malignancies in this situation is the subject of some debate. Early treatment of port wine stains with ionising radiation has been implicated in the development of BCC. The use of the argon laser has not been implicated. We present four cases of BCC in port wine stains, one previously treated with an argon laser, and discuss the possible aetiological factors.