Intracranial extramedullary haematopoiesis in postpolycythemic myelofibrosis

Abstract Extramedullary haematopoiesis (EMH), which may occur in various types of haemodyscrasia and dyshaematopoiesis, is generally seen in the spleen, liver and lymph nodes, but rarely within the cranium. This is a case of intracranial EMH in a patient with secondary myelofibrosis which developed after the treatment of polycythaemia rubra vera.