[Unclassified chronic myeloproliferative Ph(-); i(17q); +8 syndrome with mixed myelo-megakaryoblastic crisis--case report].

We present a case of a 17-year old patient with extreme hepatosplenomegaly, hyperthrombocytosis, hyperleucocytosis and the presence of myelo- and megakaryoblasts in the peripheral blood film. Numerous complications that occurred in the course of the disease made cytostatic treatment difficult. Since Ph chromosome and hybrid gene bcr/abl were absent, the diagnosis of unclassified chronic myeloproliferative syndrome in the phase of blast crisis was established. Immunophenotyping confirmed a mixed myelo- megakaryoblastic character of the crisis. In the differential diagnosis other myeloproliferative syndromes were taken into account including i(17q) syndrome. The patient died after a 13-month observation due to neoplasm progression and sepsis.