Primary follicular lymphoma of the duodenum.

Follicular lymphoma, a common nodal lymphoma, is rare in the gastrointestinal tract. When seen in this location, duodenal involvement is frequent. Most patients have localized disease, and survival appears to be excellent even without treatment. Although the outcomes are improved, the morphologic, immunophenotypic, and genetic features remain similar to those of nodal follicular lymphomas. We describe a woman with de novo follicular lymphoma of the duodenum and discuss the features of this remarkably indolent variant of follicular lymphoma.