Intracranial myeloid metaplasia in idiopathic myelofibrosis.

Extramedullary hematopoiesis is a common finding in idiopathic myelofibrosis and is generally found in the liver, spleen and lymph nodes, but meningeal extramedullary hematopoiesis is very rare. Some diseases may be causes of intracranial masses and diagnosis is difficult. We present a case diagnosed as intracranial and meningeal extramedullary hematopoiesis with idiopathic myelofibrosis inducing serious headache.