What does having bone marrow cells move to and enlarge the liver and spleen indicate in myelofibrosis? does this change the prognosis?

Advanced stage: When bone marrow cells move to spleen/liver, it may mean bone marrow is failing & cannot make blood cells effectively. Therefore, the spleen & liver take over to do the job- then they get enlarged & blood count also drops & many patients may require transfusions. Patients may have fevers etc. Treatment is available for enlarged spleen & fevers. (jakafi).Younger patients may need transplant.

Yes: If you have mf and now getting splenomegaly it means disease is progressing. If you are the patient at age 37 you need to explore definitive treatment strategy ask for bone marrow transplant referral.