Cutaneous extramedullary hematopoiesis presenting as leg ulcers.

A case of cutaneous extramedullary hematopoiesis was manifest as bilateral leg ulcers in a patient with myelofibrosis. Six similar cases have been reported previously, although the new case represented an entirely new clinical manifestation. The cutaneous lesions were previously described as erythematous papules, nodules, or plaques. Among these seven cases, myeloid series only or myeloid and erythroid series, with of without megakaryocytes, were found in the cutaneous lesions. All three marrow elements were observed in the ulcers of the present case. The possibility of extramedullary hematopoiesis should be considered in a patient who has myelofibrosis with unusual cutaneous eruptions.