This retrospective single-center study compared thromboembolic and hemorrhagic complications, survival and causes of death in a cohort of 102 consecutive patients with myeloproliferative disorders (MPD). We included 17 patients with essential thrombocythemia (ET), 59 with polycythemia vera (PV), and 26 with osteomyelofibrosis (OMF). The median follow-up was 3.7 years. Estimated 8-year probability of complications for the entire cohort was 80 +/- 11% (95% confidence interval), without significant differences among MPD subgroups. The rate of thromboembolic complications, expressed as the number of events per 100 patient years, was 16.7 for patients with PV, 13.8 for OMF, and 7.5 for ET. Fifty-four percent of thromboembolic events in PV involved cerebral or limb arteries. The rate of bleeding complications was highest in patients with OMF (31.8 per 100 patient years), followed by ET and PV (11.8). Ninety percent of bleeding episodes affected the skin. mucosal membranes, and the gastrointestinal tract. Eight-year survival was highest in ET with 91 +/- 17%, followed by PV (66 +/- 18%) and OMF (40 +/- 31%) (P< 0.01). Twenty-four patients died during the observation period, and fatal thrombosis (in five patients) represented the leading cause of death. Only two patients with MPD died from fatal hemorrhage and one from acute leukemia. We conclude that survival is highest in ET and lowest in OMF. Both thromboembolic and hemorrhagic complications are frequent. However, thrombosis appears to be more often fatal than bleeding complications. Prophylaxis of thromboembolic events remains a key issue in the management of MPD.

Background: Hyponatremia is a known complication of cytotoxic treatment. We observed this side effect in a patient treated with bortezomib. This paper gives an overview of the literature on antineoplastic agents that have been associated with hyponatremia. Case Report: A 77-year-old female patient with mantle cell lymphoma was admitted with rapidly progressive ataxia, slurred speech, and confusion. 43 days earlier, a second-line treatment with the proteasome inhibitor bortezomib had been started. Neurological examination revealed no focal deficits. Laboratory evaluation showed a combined electrolyte disorder with severe hyponatremia (sodium 112 mmol/l). Results: A syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was diagnosed, and bortezomib was identified as its cause. The drug was consecutively stopped. CT scan showed a complete remission (CR). Since, the patient has remained in a CR without further tumor-specific treatment. Conclusion: Hyponatremia may be a side effect of treatment with bortezomib and a number of other antineoplastic agents. Because of limited data available, accurate incidences of this complication are not known.