DFL is due to the accumulation of monoclonal (i.e. cells descendent from a single ancestral cell) centrocytes and their precursor centroblasts to form follicle-like structures in the duodenum and other parts of the small intestine. In virtually all cases of the disease, these cells bear a pathological genomic abnormality that is typical of most but not all forms of<unk>  lymphoma, i.e. a translocation between position 32 on the long (i.e. "q") arm of chromosome 14 and position 21 on chromosome 18's q arm. This t(14:18)q32:q21) translocation juxtaposes the B-cell lymphoma 2 (BCL2) gene on chromosome 18 at position q21.33 near to the immunoglobulin heavy chain locus (IGH@) on chromosome 14 at position q21, and in consequence causes the overexpression of this gene's product protein, BCL2 apoptosis regulator (i.e. Bcl2). Blc2 functions to inhibit programmed cell death thereby prolonging cell survival. The overexpression of Bcl2 in the B-cells of ISFL is thought to be a critical factor in their pathological accumulation and subsequent malignant progression. Gene expression profiling studies find that the tissues involved in DFP highly express certain genes that are unlike those expressed by the tissues in other forms of<unk>  lymphoma and more closely match those expressed by the tissues in MALT lymphoma, a lymphoma involving the mucosa-associated lymphoid tissue of the GI tract, airways, conjunctiva, vulvo-vagina tract, and skin. The highly express genes in both disorders include: 1) CCL20, a chemokine that is a chemoattractant for lymphocytes and 2) MAdCAM-1, a cell adhesion protein on mucosal vascular endothelial cells that binds to the α4β7 homing receptor on lymphocytes. and 3) C-C chemokine receptor type 6, which is the lymphocyte receptor for CCL20. Working together, these genomic abnormalities are thought to deliver virtually immortalized centrocytes and centroblases to the involved GI tract tissues in<unk> . Furthermore, The malignant cells in DFL express immunoglobulin heavy chains made from specific rather than various gene segments of the IGH@ region on chromosome 14. In one study, for example, heavy chains made form VH4 and VH5 segments were expressed in a higher percentage of DFL cases than expected. These findings, along with those showing similarities in the profiles of highly expressed genes in DFL and mantle cell lymphoma suggest that DFL, like mantle cell lymphoma, develops as a consequence of chronic inflammation and specific antigen stimulation. In support of this possibility, there have been reports that DFL regresses in patients who are successfully treated for concurrent Helicobacter pylori infestation of the GI tract.
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