The unusual appearance of extensive skin ulcerations was observed in 17 patients with chronic myelogenous leukemia on continuous chemotherapy with hydroxyurea. The strict relationship between ulcers and therapy was proved by the complete (14 cases) or almost complete (3 cases) healing of lesions after therapy was discontinued. The possible pathogenetic mechanisms responsible for skin alterations are considered. The particular importance of the continuous hydroxyurea administration modality clearly emerges, suggesting the use of different administration modalities to reduce such serious side effects
