AGGRESSIVE SQUAMOUS-CELL CARCINOMAS DEVELOPING IN PATIENTS RECEIVING LONG-TERM AZATHIOPRINE

We report three patients who developed unusually aggressive squamous c ell carcinomas after receiving long-term azathioprine treatment for de rmatological disorders. Two patients gave a history suggestive of mode rate to excessive sun exposure, and the third suffered from chronic ac tinic dermatitis. Hence, ultraviolet light damage may have been a sign ificant cofactor in the development of these malignancies. Careful fol low-up is necessary in patients who are taking azathioprine long term, and who have previously been excessively exposed to ultraviolet light (UVL), or in whom future exposure is likely to be excessive. We sugge st that strict sun avoidance measures are followed by patients on long -term azathioprine, or that alternatives to azathioprine therapy are c onsidered, especially in individuals inherently at risk of UVL damage, and in those already showing clinical signs of such damage.