A patient initially treated for iron deficiency anemia was later found to have myelofibrosis. She developed increasing splenomegaly and then a mass in the right iliac fossa for which a right hemicolectomy was performed. Histopathology demonstrated extramedullary hemopoiesis in the spleen and cecum. The patient subsequently developed a protein-losing enteropathy and she deteriorated and died 14 mths later. Autopsy was not performed.