DISEASE CHARACTERISTICS: Histologically confirmed primary amyloidosis Must have presence of paraprotein in serum or urine determined by immunoelectrophoresis/immunofixation No primary amyloidosis manifested only by carpal tunnel syndrome or purpura No history of secondary, familial, or localized amyloidosis No evidence of overt multiple myeloma: Lytic bone disease or pathological fractures OR At least 30% plasma cells in bone marrow

PATIENT CHARACTERISTICS: Age: 18 to 70 Performance status: ECOG 0-2 Life expectancy: Not specified

Hematopoietic: Absolute granulocyte count at least 1000/mm3 Platelet count at least 100,000/mm3 Hepatic:

Bilirubin no greater than 2.0 mg/dL Alkaline phosphatase no greater than 1000 u/L or less than 4 times upper limit of normal Renal: Creatinine no greater than 2.0 mg/dL Cardiovascular: Confirmed by echocardiogram: Ejection fraction at least 50% Interventricular septal thickness no greater than 15 mm No New York Heart Association classification II-IV Pulmonary: DLCO at least 50% FVC at least 60% FEV1 at least 55% Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No active infection No other malignancy within the past 5 years except surgically treated carcinoma in situ of the cervix, nonmelanoma skin cancer, or indolent prostate cancer No known sensitivity to E. coli derivatives

PRIOR CONCURRENT THERAPY: Biologic therapy: Prior interferon allowed Chemotherapy: At least 4 weeks since prior melphalan Lifetime cumulative dose of melphalan no greater than 150 mg No greater than 2 prior courses of chemotherapy Endocrine therapy: Prior dexamethasone allowed Radiotherapy: Not specified Surgery: Not specified