 Protocol involves 6 courses of rituximab and bendamustine with 26 days interval between each course one cycle continues 28 days. Control examination will be performed every two courses 28, 56, 84 days of treatment and will include physical examination, monitoring of clinical blood tests, biochemical blood tests, computed tomography, ultrasonography, in patients with gastrointestinal tract involvement - fibrogastroduodenoscopy and colonoscopy. Efficacy of therapeutic impact will be estimated as rates of complete remission, partial remission, stable disease or progression based on tumor size reduction comparing with pretreatment data and evaluated using computed tomography and expressed as a percentage. Patients with partial or complete remission or stable disease after 2 courses continue treatment. Patients with tumor progression excluded from issue. Patients which achieved a complete remission after 2 courses may end treatment after 4 courses. 