histological staging of bone and bone marrow lesions at time of diagnosis enables one to confirm long survival of cases with hyperplasia ( group i ) and more severe prognosis for advanced myelofibrosis ( that is both groups ii and iii considered together ) but does not enable to establish a significative difference between medium survival of cach group ii and iii considered separately .
C0005953
bone marrow
C0001815
myelofibrosis