[A lower-leg ulcer during hydroxyurea therapy for essential thrombocythemia].

A skin ulcer of the lateral malleous developed in a 61-year-old man receiving hydroxyurea for essential thrombocythemia. In the past, skin ulcers have been reported in patients with chronic myeloproliferative diseases, including essential thrombocythemia, who had been treated with hydroxyurea. In the current case, vasculitis or thrombi in vessels of the biopsied specimen of the lower leg were not observed, and the patient required skin-graft operation. Accordingly, we concluded that the skin ulcer might be due to the administration of hydroxyurea. Thus, the dose of hydroxyurea was decreased.