Melphalan, Lenalidomide, and Dexamethasone in Treating Patients With Primary Systemic Amyloidosis

Inclusion Criteria: DISEASE CHARACTERISTICS: * Diagnosis of primary systemic amyloidosis PATIENT CHARACTERISTICS: * Not pregnant * Negative pregnancy test * Able to tolerate an anticoagulation regimen (e.g., 325 mg of aspirin per day, therapeutic warfarin, or low molecular weight heparin) PRIOR CONCURRENT THERAPY: * Recovered from prior therapy * Permanent or stable side effects/changes allowed * Prior chemotherapy, thalidomide, lenalidomide, or steroids for amyloidosis allowed * More than 4 weeks since prior and no other concurrent cytotoxic chemotherapy or radiotherapy Exclusion Criteria: * No secondary or familial amyloidosis * No multiple myeloma (≥ 30% plasma cells in bone marrow biopsy or lytic bone lesions) * No prior cumulative doses of oral melphalan \> 200 mg * No more than one prior course of high-dose melphalan with stem cell transplant