<unk>  (DFL) is a form of lymphoma in which certain lymphocyte types, the B-cell-derived centrocytes and centroblasts, form lymph node follicle-like structures principally in the duodenum and other parts of the small intestine. It is an indolent disease which on rare occasions progresses to a more aggressive lymphoma that spreads beyond these originally involved sites. The disorder now termed DFL had been considered to be a follicular lymphoma that develops in one or more sites of the GI tract (i.e. stomach, duodenum, jejunum, small intestine, large intestine and rectum) as well as in various sites outside of the GI tract; this contrasts with other forms of follicular lymphoma which do not involve the GI tract. The disorder was regarded as a subtype of follicular lymphoma termed primary intestinal follicular lymphomas or Primary gastrointestinal tract follicular lymphomas. However, follicular lymphomas of the duodenum and other parts of the small intestine differ from the other forms of primary intestinal lymphomas in that they are indolent, highly localizes disorders that have a low rate of progression to a systemic disease. In consequence, the World Health Organization (2017) kept the more widespread primary intestinal lymphomas within the follicular lymphoma category and reclassified<unk> -/small intestinal-localized lymphoma as a distinct disease entity, DFL. DFL, while currently considered a malignant disease, has many clinical features which are more similar to the benign predecessor of follicular lymphomas viz., in situ follicular lymphoma, than to follicular lymphoma. Like in situ follicular lymphoma, DFL is most commonly a symptom-free disease that is diagnosed incidentally in patients who are undergoing endoscopy for other reasons. Also like in situ follicular lymphoma, DFL may in rare cases regress spontaneously or progress to a more serious and aggressive form.
Duodenal-type follicular lymphoma
MALT lymphoma
Monomorphic epitheliotropic intestinal T cell lymphoma
Pediatric-type follicular lymphoma
Splenic marginal zone lymphoma
Nodular lymphocyte predominant Hodgkin lymphoma
Nodal marginal zone B cell lymphoma
Indolent lymphoma