Cyclosporin A and cutaneous malignancy

Cyclosporin A has been demonstrated to be an effective alternative to conventional immunosuppressive agents, such as azathioprine and prednisolone, in promoting successful organ transplantation. Although the association between immunosuppression and the development of skin malignancy has been well documented, the cutaneous carcinogenic potential of cyclosporin remains uncertain. This report concerns two recipients of renal allografts, in whom conversion from azathioprine and prednisolone to cyclosporin A was followed by the development of a variety of hyperplastic, dysplastic and malignant cutaneous lesions. These ranged from a keratoacanthoma with small foci of dysplasia and viral wartsshowing marked dysplastic changes, to carcinoma in situ and frank invasive anaplastic squamous cell carcinoma. Furthermore, in both cases the distribution of these proliferative lesions was confined to sun‐exposed regions of the body. Although both subjects were immunosuppressed for 8 and 12 years respectively prior to the change in their therapy, the temporal relationship between conversion and the appearance of dysplastic and malignant lesions provides strong circumstantial evidence for incriminating cyclosporin A particularly in their genesis. In addition, their localizaton to sun‐exposed areas suggests that ultraviolet light plays a role in their pathogenesis and highlights the need for sun avoidance in transplanted patients.