It is crucial to role out CML by performing the bcr gene rearrangement test, since the therapeutic approach in CML is very different compared to therapy in essential thrombocythemia, polycythemia vera, or agnogenic
myeloid metaplasia with myelofibrosis.
It can be distinguished from agnogenic
myeloid metaplasia by the absence of splenomegaly, teardrop RBCs and leukoerythroblastosis in peripheral blood smears, and from acute megakaryoblastic leukemia by the absence or small percentages of blasts of megakaryocytic origin .
Cytogenetic studies and their prognostic significance in agnogenic
myeloid metaplasia: a report on 47 cases.
Myelofibrosis (also called agnogenic
myeloid metaplasia) is a myeloproliferative disorder in which the bone marrow is initially over-active but then develops scar tissue (fibrosis).
Hypothesis: splenic filtration and the pathogenesis of extramedullary hematopoiesis in agnogenic
Excluded from this discussion are polycythemia vera, essential thrombocythemia, and agnogenic
myeloid metaplasia, which are also considered myeloproliferative disorders along with CLMO, but are generally not leukemic.