Scrotal Ulcers Arising during Treatment with All-trans Retinoic Acid for Acute Promyelocytic Leukemia.

All-trans retinoic acid (ATRA) is effective in approximately 90% of the cases of acute promyelocytic leukemia (APL) with a low incidence of adverse effects. We report a patient with APL who developed skin ulcers of the scrotum concomitant with high fever during treatment that included ATRA. Severe fever was promptly alleviated with discontinuation of ATRA, while the ulcers improved gradually over 3 months. As the clinical features are similar to those of Sweet's syndrome, we should be aware of the possibility that this rare adverse effect may occur in the treatment with ATRA.