Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histochemical diagnosis of AL amyloidosis based on detection of green birefringent
material in Congo red-stained tissue specimens by polarizing microscopy

- Measurable disease, as defined by one of the following:

- Serum monoclonal protein ≥ 1.0 g by serum electrophoresis

- Urine monoclonal protein > 200 mg by 24-hour urine electrophoresis

- Serum immunoglobulin free light chain ≥ 10 mg/dL AND abnormal serum
immunoglobulin kappa to lambda free light chain ratio

- Symptomatic organ involvement with amyloid to justify therapy

- May include liver involvement, cardiac involvement, renal involvement, grade 1
peripheral neuropathy, or soft tissue involvement

- Must have more than skin purpura or carpal tunnel syndrome

- No amyloid-specific syndrome, such as carpal tunnel syndrome or skin purpura, as only
evidence of disease

- Vascular amyloid only in a bone marrow biopsy specimen or in a plasmacytoma is not
indicative of systemic amyloidosis

- No clinically overt multiple myeloma (i.e., monoclonal BMPC > 30%, bone lesions, or
hypercalcemia)

PATIENT CHARACTERISTICS:

- ECOG performance status 0-2

- ANC ≥ 1,000/μL

- Platelet count ≥ 75,000/μL

- Creatinine < 3.0 mg/dL

- Not pregnant

- Negative pregnancy test

- Fertile patients must use two acceptable methods of contraception for ≥ 28 days prior
to, during, and for ≥ 28 days after completion of study treatment

- No nursing during and for ≥ 28 days after completion of study treatment

- No blood, semen, or sperm donation during and for ≥ 28 days after completion of study
treatment

- No malignancies within the past 5 years except treated basal cell or squamous cell
carcinoma of the skin, or carcinoma "in situ" of the cervix or breast

- No neuropathy ≥ grade 2, defined as motor neuropathy (symptomatic weakness
interfering with function, but not interfering with activities of daily living [ADL])
or sensory neuropathy (sensory alteration or paresthesia [including tingling],
interfering with function, but not interfering with ADL)

- No uncontrolled infection

- No syncope within the past 30 days

- No known hypersensitivity to thalidomide, including desquamating rash with
thalidomide in the past

- No known seropositivity for HIV

- No active hepatitis A, B, or C

- No New York Heart Association class III or IV heart disease

- No venous thromboembolic event within the past 42 days

- Able to take aspirin (81 or 325 mg) daily as prophylactic anticoagulation - Patients
intolerant to aspirin may use low molecular weight heparin

PRIOR CONCURRENT THERAPY:

- No prior lenalidomide

- More than 2 weeks since prior and no other concurrent anticancer agents or treatments

- More than 4 weeks since prior experimental agents

- No other concurrent corticosteroids except chronic steroids (maximum dose 20 mg/day
of prednisone equivalent) for disorders other than amyloidosis (e.g., adrenal
insufficiency or rheumatoid arthritis)