[Multiple myeloma predominantly involving the spleen].

Extramedullary disease is an uncommon manifestation in multiple myeloma (MM) and can be observed at onset or develop at disease progression or relapse. Splenic involvement is very rare. The paper describes a 52-year-old female patient with MM who in 1990 was diagnosed with monoclonal gammopathy of undetermined significance with IgGkappa secretion and a considerably enlarged spleen. Specific therapy with bortezomib and dexamethasone was initiated in 2006 and proved to be inefficient. After splenectomy there was a 50% reduction in IgGkappa concentration. Splenic histological examination revealed monoclonal infiltration by the pleomorphic plasma cells expressing a kappa light chain.