[Myeloproliferative syndrome]

Division of myeloproliferative syndrome is recommended based on 195 observer cases: A) Secondary myeloproliferative syndrome usually accompanies marrow carcinosis. It is characterized by non-destructive embryonal-type myeloproliferation occurring even outside the marrow excepting lymph nodes as a rule. There are neither specific changes in karyogram nor in alkaline phosphatase positivity. B) Idiopathic myeloproliferative syndrome is characterized (in comparison to A) by dysplastic changes especially in megakaryocytic line; it develops slowly tending to malignancy, namely leukemia or erythroleukemia that keep (unlike spontaneous leukemia) more severe dysplastic changes of megakaryocytes. Alkaline phosphatase is increased, atypical karyogram is not changed in Ph 1 region. C) Malignant neoplastic myeloproliferation of panmyelosis type is a primary destructive process akin to myelosis. Alkaline phosphatase is decreased, there are typical Ph 1 changes in karyogram and tumorous lymph node infiltration. Secondary myeloproliferative syndrome follows rarely and a mixed picture can be observed then, of course without severe megakaryocytic dysplasia. D) Myelofibrosis is an uncharacteristic final picture of various origin which neither develops in myeloproliferative syndrome or substitutionary extramedullar hemopoesis. Hesitation in oncological typing of idiopathic myeloproliferative syndrome cannot influence its nosological individuality. Exceptional and unexpected positive markers (alkaline phosphatase, Ph 1) occur in diagnostical practice from time to time; being unexplained they hinder from precise typing.