Cutaneous extramedullary hematopoiesis with a preponderance of atypical megakaryocytes in myelofibrosis

Extramedullary hematopoiesis was found in the cutaneous papulonodular eruption of a 72-year-old man with myelofibrosis. This is the first reported case to show a preponderance of atypical megakaryocytes in skin lesions. The patient was also unusual in that he had marked generalized lymphadenopathy. The skin lesions almost disappeared after treatment with hydroxyurea.