Thrombotic complications in multiple myeloma: a report of three cases and review of the literature.

The risk of venous thromboembolism (VTE) increases in the presence of plasma cell dyscrasias. Monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) share an intrinsic increased risk of VTE. Treatment with thalidomide and lenalidomide further increases the incidence of VTE in certain MM patient subsets. The pathogenesis remains unclear, but probably involves several factors such as activation of procoagulant factors, acquired activated protein C resistance, and inflammation. In addition to general risk factors for VTE, such as older age, immobility, surgery, and inherited thrombophilia, there are some MM-specific and treatment-related factors that contribute to the increased risk. The risk for VTE is high under treatment with thalidomide or lenalidomide in combination with dexamethasone or multi-agent chemotherapy. We report 3 cases of MM with VTE with review of the literature. This review highlights the risk factors for VTE in MM and general, disease-specific and treatment-related mechanisms for thrombosis.