Patients receive oral lenalidomide once daily on days 1-21, rituximab IV on day 1, oral cyclophosphamide once daily on days 1, 8, and 15, and oral dexamethasone once daily on days 1, 8, 15, and 22. Treatment repeats every 28 days for up to 12 courses in the absence of disease progression or unacceptable toxicity.