Chronic myeloproliferative syndromes include a series of neoplasms originating in the hematopoietic stem cell. Damaged stem cells affects the erythroid, granulocytic and megakaryocytic lines, from which are derived the red blood cells, white blood cells and platelets respectively. This has a global affect on all the myeloid lines with a proliferation of these three lines mentioned, although one of them will predominate in each of the various diseases.
Furthermore, to a greater or lesser degree, bone marrow fibrosis is present in all of them, probably as a reactive phenomenon to the neoplastic proliferation. This proliferation also explains the frequent existence of splenomegaly and hyperuricemia, as well as the increased levels of certain serum markers (LDH, vitamin B12 and FAG).
Damaged stem cells can also explain the not infrequent transformation of one entity into another, and the observation of elusive clinical symptoms that make diagnosis more difficult.
They are chronic diseases with a tendency to progress to global bone marrow failure or, more frequently, an acute leukaemia.