DISEASE CHARACTERISTICS:

• At least 1 of the following diagnoses:

  • Multiple myeloma

    • Stage II or III disease

    • At least 1 of the following must be present:

      • Serum M-protein of IgG, IgA, IgD, IgE greater than 1.0 g/dL
      • Urinary M-protein (Bence-Jones) at least 200 mg/24 hours
    • No IgM peaks except in patients who have physiologic criteria to support a diagnosis of multiple myeloma (e.g., bony lesions, myeloma kidney-cast nephropathy, absence of adenopathy [unless pathology-proven to be plasma cell infiltration])
    • No monoclonal gammopathy of undetermined significance
    • No indolent or smoldering myeloma
    • No disease progression on prior thalidomide or dexamethasone

  • Histologically confirmed primary systemic amyloidosis

    • No senile, secondary, localized, dialysis-related, or familial amyloidosis

    • No severe cardiac involvement

      • No pre-exertional syncope, ventricular arrhythmia, or symptomatic pleural effusions associated with cardiac involvement

  • Light Chain Deposition Disease alone or in combination with multiple myeloma meeting the following criteria:

    • Deposition of granular material containing free light chains/immunoglobulins that did not bind Congo red
    • Evidence of plasma cell dyscrasia (i.e., monoclonal gammopathy in the serum or urine by immunofixation electrophoresis and/or clonal plasmacytosis) on bone marrow biopsy by immunohistochemistry and/or elevated serum-free light chain concentration
• Must have been diagnosed within the past year
• Concurrent enrollment in the myeloma repository protocol SWOG-S0309 must be offered

PATIENT CHARACTERISTICS:

Age

• 18 and over (patients with amyloidosis only OR patients with amyloidosis and multiple myeloma OR patients with multiple myeloma only with poor renal function) OR
• 70 and over (patients with multiple myeloma only with or without poor renal function)

Performance status

• Zubrod 0-2

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count at least 1,000/mm^3
• Platelet count at least 100,000/mm^3

Hepatic

• Bilirubin no greater than 2.5 times upper limit of normal (ULN)
• SGOT or SGPT no greater than 2.5 times ULN

Renal

• No hemodialysis within 2 hours of melphalan or stem cell infusion

Cardiovascular

• See Disease Characteristics
• Hemodynamically stable (i.e., systolic blood pressure > 90 mm Hg in a lying position within the past 42 days)
• No myocardial infarction within the past 6 months
• No congestive heart failure
• No arrhythmia refractory to medical therapy
• LVEF greater than 45% by echocardiogram or MUGA

Pulmonary

• See Disease Characteristics
• No history of chronic obstructive or chronic restrictive pulmonary disease
• Pulmonary function studies (e.g., FEV_1 and FVC) at least 50% of predicted
• DLCO at least 50% of predicted
• Normal high resolution CT scan of the chest and acceptable arterial blood gases (i.e., PO_2 greater than 70) required for patients unable to complete pulmonary function tests due to bone pain or fracture

Other

• Not pregnant or nursing
• Negative pregnancy test

• Fertile patients must use effective contraception

  • Multiple myeloma patients receiving thalidomide must use 2 methods of effective contraception for at least 4 weeks before, during, and for at least 4 weeks after discontinuation of thalidomide
• HIV negative
• No other concurrent significant medical condition
• No concurrent uncontrolled life-threatening infection
• No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer currently in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

• See Disease Characteristics

Chemotherapy

• See Disease Characteristics
• Prior cumulative melphalan dose no more than 200 mg
• No other concurrent chemotherapy

Endocrine therapy

• See Disease Characteristics
• No concurrent hormonal therapy

Radiotherapy

• No concurrent radiotherapy

Surgery

• Not specified

Other

• Recovered from prior therapy
• Prior or concurrent bisphosphonates allowed