Inclusion Criteria:

1. histologically proven diagnosis of CD20-positive marginal zone B-cell lymphoma of
MALT type arisen at any extranodal site

2. any stage (Ann Arbor I-IV)

3. either de novo, or relapsed disease following local therapy (including surgery,
radiotherapy and antibiotics for H. pylori-positive gastric lymphoma)

4. no evidence of histologic transformation to a high grade lymphoma

5. measurable or evaluable disease

6. age > 18

7. life expectancy of at least 1 year

8. ECOG performance status 0-2

9. no prior diagnosis of neoplasm within 5 years, except cervical intraepithelial
neoplasia type 1 (CIN1) or localized non-melanomatous skin cancer

10. no prior chemotherapy

11. no prior immunotherapy with any anti-CD20 monoclonal antibody

12. no prior radiotherapy in the last 6 weeks

13. no corticosteroids during the last 28 days, unless prednisone chronically
administered at a dose <20 mg/day for indications other than lymphoma or
lymphoma-related symptoms

14. no evidence of clinically significant cardiac disease, as defined by history of
symptomatic ventricular arrhythmias, congestive heart failure or myocardial
infarction within 12 months before study entry

15. no evidence of symptomatic central nervous system (CNS) disease

16. no impairment of bone marrow function (WBC >3.0x109/L, ANC >1.5x109/L, PLT
>100x109/L), unless due to lymphoma involvement

17. no major impairment of renal function (serum creatinine <1,5x upper normal) or liver
function (ASAT/ALAT <2,5 upper normal, total bilirubin <2,5x upper normal), unless
due to lymphoma involvement

18. no evidence of active opportunistic infections

19. no known HIV infection

20. no active HBV and/or HCV infection

21. no pregnant or lactating status

22. appropriate contraceptive method in women of childbearing potential or men

23. absence of any psychological, familial, sociological or geographical condition
potentially hampering compliance with the study protocol and follow-up schedule;
those conditions should be discussed with the patient before registration in the
trial

24. informed consent must be given according to national/local regulations before
randomization