Clinical characteristics and outcomes of Brazilian patients with duodenal-type follicular lymphoma: a multicenter retrospective study.

Duodenal-type follicular lymphoma (DFL) is a rare subtype classified by the 5th edition of the WHO and international consensus classifications of lymphoid neoplasms, typically presenting as localized disease with favorable outcomes. This multicenter retrospective study examines 53 Brazilian DFL patients with a median age of 58.2 years (33-85), with males comprising 50% (n = 27). According to Lugano GI tract classification, 40 patients (75%) were stage I. Median follow-up was 2.9 years (range 0.1-11). Incidental diagnosis occurred in 28 patients (52.8%) during routine endoscopy; 24 patients (45%) presented mild gastrointestinal symptoms. Treatments included watchful waiting (32 patients, 60.4%), rituximab monotherapy (15 patients, 28.3%), radiotherapy (three patients, 5.7%), and chemoimmunotherapy (three patients, 5.7%). Three patients experienced disease progression; watchful waiting showed three spontaneous remissions. No deaths occurred during follow-up. This study, the first from Latin America, demonstrates a good prognosis across treatments, highlighting Watchful waiting's effectiveness.