OBJECTIVES: I. Determine the toxic effects of rituximab and dexamethasone in patients with recurrent or refractory indolent non-Hodgkin's lymphoma. II. Determine the objective tumor response rate and duration of response at 2 months after initiation of therapy, and the percentage of patients with progressive disease. III. Determine the maximum response, duration of response, and progression free interval for patients who have not progressed after 4 weeks of therapy. IV. Determine the failure-free and overall survival of these patients on this regimen. V. Compare the response rate and survival rates to results for similar patients (historical and concurrent) who have received 4 weeks of rituximab without dexamethasone, and patients who did not receive maintenance rituximab.