HD Melphalan and SCT in Patients With IGDD or LCDD

Inclusion Criteria: DISEASE CHARACTERISTICS: * Histologically confirmed light-chain deposition disease based on the following criteria: * Deposition of granular material containing free light-chain (FLC) immunoglobulins that did not bind Congo red * Evidence of a plasma cell dyscrasia, as defined by any of the following: * Monoclonal gammopathy in the serum or urine by immunofixation electrophoresis * Clonal plasmacytosis on bone marrow biopsy by immuno-histochemical * Elevated serum levels of FLC * Patients may enroll after stem cell collection (SCC) if all prestudy requirements are completed prior to starting SCC (i.e., ≥ 2.5 x 10\^6 cells available for transplantation) PRIOR CONCURRENT THERAPY: * Prior chemotherapy with alkylating agent allowed provided there is no evidence of myelodysplastic syndromes * Prior total dose of melphalan \< 300 mg * More than 4 weeks since prior cytotoxic therapy and recovered PATIENT CHARACTERISTICS: * Performance status 0-2 * Left Ventricular Ejection Fraction (LVEF) ≥ 45% within the past 90 days * diffusing capacity of lung for carbon monoxide (DLCO) ≥ 50% Exclusion Criteria: * No overt multiple myeloma, as defined by any of the following: * Greater than 30% bone marrow plasmacytosis * Extensive (i.e., \> 2) lytic lesions * Hypercalcemia * No myocardial infarction, congestive heart failure, or arrhythmia refractory to therapy within the past 6 months * No prior malignancy except adequately treated basal cell…