Multiple myeloma in sickle cell syndromes.

Multiple myeloma (MM) is rare among patients with sickle cell syndromes (SCS). We describe six Greek sickle cell patients aged 56 to 65 years: five haemoglobin Sbeta+thalassaemia (HbSbeta+ (thal), one sickle cell anaemia (HbSS), who developed MM (three IgGkappa, one IgGlambda, one IgAkappa, and one IgGK-IgAK (biclonal). Our HbSbeta+thal cases, represent the first reported association of this entity with MM. Generalized bleeding diathesis, stroke, grand mal seizures, bone marrow necrosis and other clinical manifestations due to hyperviscosity aggravated by sickle cell vasoocclusion were treated by plasmaphereses and exchange blood transfusions. The increase of mean survival in SCS patients due to the current medical facilities may have an impact on the incidence of MM among them, if a pathogenetic link between the two conditions exists. All our patients carried a diagnosis of cholelithiasis which may predispose to MM; two of them progressed from a monoclonal gammopathy of undetermined significance (MGUS) to MM. Further studies are needed in order to understand the relationship between SCS and MM.