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 h
as been implicated in the development of BCC. The use of the argon laser ha
s not been implicated. We present four cases of BCC in port wine stains, on
e previously treated with an argon laser, and discuss the possible aetiolog
ical factors. (C) 2001 The British Association of Plastic Surgeons.