Background: Basal cell carcinoma occurring in port wine stain is extremely rare but has been reported after radiotherapy for port wine stain.
Objective: The objective was to present 55-year-old man with a facial port wine stain who had multiple treatment sessions with both the argon laser and the pulsed dye laser and subsequently developed a recurrent multifocal basal cell carcinoma and highlight the treatment carried out and its effects on the outcome.
Methods: We describe the history of the patient's port wine stain treatment, the development of skin cancer within it, and the different modalities of therapy carried out.
Results: The patient developed basal cell carcinoma in his port wine stain. The possibility of a causal link between laser treatment and this skin cancer was considered but it was discovered that he had had radiotherapy treatment of his birthmark at age 9. The basal cell carcinoma was successfully treated.
Conclusion: This case of a clinically indistinct multifocal basal cell carcinoma arising within facial port wine stain was most likely due to previous radiotherapy treatment as a child, rather than laser treatment. Careful treatment history should identify such patients who should be followed-up for development of skin cancer.