Morbus Castleman is a benign non-clonal lymphoproliverative disorder. Immunomodulatory and antiproliferative drugs are used to treat this plasma cell disorder. We report the case of a 46-year old female patient with multicentric Castleman's disease and limb ischemia. Thrombotic occlusions of the popliteal and tibioperoneal arteries were treated by percutaneous thrombus aspiration. We discuss the role of increased interleukin-6 plasma levels during therapy with Tocilizumab, an antibody to interleukin-6 receptor, as a potential cause for arterial thrombosis.