Primary follicular lymphoma of the duodenum: a case report and review of literatures.

Follicular lymphoma (FL) is one of the most common types of non-Hodgkin lymphoma (NHL). The gastrointestinal tract is the most involved extra-nodal site of NHL. Primary duodenal FL (DFL) is a rare entity with only a few reported cases. It mainly involves the second part of the duodenum and has an excellent prognosis. We report the case of a 74-year-old man who underwent esophagogastroduodenoscopy. Endoscopic findings revealed multiple small whitish mucosal nodules which were detected around the major duodenal papilla. Biopsy of these lesions was compatible with grade I FL. Further investigation failed to demonstrate any evidence of nodal or systemic involvement; thus, the clinical staging was stage I, according to the Lugano staging system. A "watch and wait" policy was chosen. Neither lesion aggregation nor lymphadenopathy was noted during the 5-year follow-up period. In conclusion, this was an uncommon case of DFL with an indolent nature and excellent prognosis. However, further studies are needed to clarify the characteristics, prognosis, and therapeutic approach.