[A 52-year old female patient with recurrent shock of unclear origin, hemoconcentration and hypoalbuminemia].

Systemic capillary leak syndrome is a rare life threatening condition of unknown etiology. It was firstly described by Clarkson et al in 1960. It is characterised by recurrent attacks of severe hypovolemic shock, hemoconcentration and hypalbuminemia, caused by a sudden reversible increase in capillary permeability and shift of fluid and macromolecules to the extravascular compartment. A monoclonal paraprotein is always detectable in the serum of patients, without evidence of multiple myeloma. We describe the course of a patient, who died at a severe attack despite of prophylactic treatment after 25 months of illness. Application of cytostatics should be considered if prophylactic treatment fails even if there is no evidence of progression to multiple myeloma.