Due to an increasing incidence and more frequent recognition by endoscopists, gastrointestinal follicular lymphoma has been established as a variant of follicular lymphoma. However, due to its rarity, there are no established guidelines on the optimal diagnostic strategy for patients with primary gastrointestinal follicular lymphoma or secondary gastrointestinal involvement of systemic follicular lymphoma. This review offers an overview and pitfalls to avoid during the initial diagnostic workup of this disease entity. Previously reported case reports, case series, and retrospective studies are reviewed and focus on the disease's endoscopic and histological features, the roles of computed tomography and positron emission tomography scanning, the clinical utility of the soluble interleukin-2 receptor, and the possible pathogenesis.
Keywords: Duodenal neoplasms; Follicular lymphoma; Gastrointestinal endoscopy; Gastrointestinal lymphoma; Intestinal neoplasms.