Lymphoma & related disorders

Extranodal organ specific lymphoma

Follicular lymphoma-duodenal type

Topic Completed: 24 February 2020

Minor changes: 19 January 2021

Copyright: 2001-2021,, Inc.

PubMed Search: Duodenal type follicular lymphoma

Mahsa Khanlari, M.D.
Jennifer Chapman, M.D.
Page views in 2020: 3,178
Page views in 2021 to date: 3,613
Cite this page: Khanlari M, Chapman J. Follicular lymphoma-duodenal type. website. Accessed November 27th, 2021.
Definition / general
  • Duodenal type follicular lymphoma is a variant follicular lymphoma (FL) characterized by:
    • Morphologic features and immunophenotype similar to nodal follicular lymphoma
    • Distinct entity in 2016 WHO
    • Unlike nodal follicular lymphoma, is almost always diagnosed at a low stage and stays localized to the small intestine
    • Treatment is local, not systemic
Essential features
  • Low grade cytology
  • Indolent clinical course
  • Usually carries the t(14;18) (q32;q21) translocation
  • Primary intestinal follicular lymphoma
ICD coding
  • ICD-10: C82.90 - Follicular lymphoma, unspecified, unspecified site
  • ICD-O: 9695/3 - Follicular lymphoma, grade 1
Pathophysiology / etiology
  • Origin from memory B cell with germinal center marker expression
  • t(14;18)(q32;q21) translocation: duodenal type follicular lymphoma is part of follicular lymphoma family
  • Immune microenvironment of duodenal type follicular lymphoma is distinct from nodal follicular lymphoma (Blood 2018;132:1695)
  • Some shared features with MALT lymphoma
    • Chronic inflammation signature
    • Restricted immunoglobulin heavy chain variable region genes (IGHV): suggests development related to chronic antigen stimulation (Cancer Sci 2014;105:608)
Diagrams / tables

Nodal Follicular Lymphoma Duodenal Follicular Lymphoma
 Grade 1 - 2 or 3   Grade 1 - 2 
 Stage III or IV   Stage I or II 
 BCL2, CD10, BCL6: Positive    BCL2, CD10, BCL6: Positive 
 AID: Positive   AID: Negative 
 CD21 stain: Dense stain in the center of
 germinal center of follicles 
 CD21 stain: Accentuated staining at the 
 periphery of germinal center of follicles 
 BCL2 and BCL6 rearrangements: +   BCL2 and BCL6 rearrangements: + 
CREBBP mutations present  CREBBP mutations present 
KMT2D mutations present   Lower KMT2D mutations present 
AID: Activation-induced cytidine deaminase
Clinical features
  • Second portion of the duodenum is the most common site
  • Asymptomatic or abdominal symptoms
  • Low grade histology (grade 1 - 2)
  • Low stage presentation
  • Incidental polyp in patients undergoing upper endoscopy
  • Multifocal involvement of the gut by polypoid and nodular lesions
  • Multiple lesions more in the jejunum and ileum rather than duodenum (J Clin Oncol 2011;29:1445)
  • Rarely ulcerated mucosal lesion
  • Solitary or multiple nodules in endoscopy (1 - 5 mm)
  • Biopsy
Prognostic factors
  • A small subset of patients (< 10%) progress to nodal disease
  • 5 year progression free survival 98% in duodenal type follicular lymphoma with restricted duodenal involvement (Cancer Sci 2011;102:1532)
Case reports
  • 34 year old man with primary multifocal small bowel follicular lymphoma discovered incidentally on diagnostic endoscopy (Clin Gastroenterol Hepatol 2017;15:A27)
  • 52 year old man with duodenal type follicular lymphoma in which histological transformation into diffuse large B cell lymphoma developed 7 years after diagnosis (Oncotarget 2019;10:3424)
  • 52 year old woman who was eventually diagnosed with primary follicular lymphoma of the duodenum showed atypical endoscopic features, namely, erosions with peripheral whitish edematous mucosa (Case Rep Med 2012;2012:582607)
  • 58 year old man who was diagnosed with duodenal type follicular lymphoma and was treated with clarithromycin monotherapy (Case Rep Oncol 2018;11:239)
  • Two approaches:
    • Watch and wait approach
    • Localized radiation with or without chemotherapy (+/-Rituximab)
Gross description
  • Almost all diagnoses are made on endoscopic biopsy
Microscopic (histologic) description
  • Several well circumscribed lymphoid aggregates
  • Composed of centrocytes (with infrequent centroblasts)
  • Lymphoma usually involves the mucosa and submucosa
  • Spares the muscularis propria
  • Neoplastic cells commonly involve duodenal villi
  • Hollowed out follicular dendritic cell meshworks (Mod Pathol 2009;22:940)
Microscopic (histologic) images

Contributed by Mahsa Khanlari, M.D.
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Small intestinal polyp

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CD10 and CD20 Immunohistochemistries

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Positive stains
Negative stains
Molecular / cytogenetics description
Sample pathology report
  • Biopsy, endoscopic, duodenum:
    • Follicular lymphoma involving duodenum (see comment)
    • Comment: The patient is a 45 year old female with history of vague abdominal pain. Histologic sections consist of endoscopic biopsies of duodenum showing involvement by an atypical lymphoid infiltrate. Lymphoid cells are arranged in a follicular distribution and consist of small lymphoid cells with mature nuclear chromatin and frequent centrocytic features. Centroblasts are rare and scattered.
    • By immunohistochemistry the atypical lymphoid cells are positive for CD20 and CD79a with coexpression of CD10, BCL6, LMO2 and BCL2. CD3 and CD5 highlight reactive T cells surrounding the neoplastic B cell aggregates. Ki67 proliferative rate is low within neoplastic follicles, ~5%. These findings support the above interpretation.
    • Correlation with clinical features and staging procedures is required to determine whether the patient’s follicular lymphoma is a primary duodenal type follicular lymphoma, or a systemic follicular lymphoma secondarily involving duodenum. In the sampled material the lymphoma is of low histologic grade (grade 1).
Differential diagnosis
Board review style question #1
    Which of the following follicular lymphoma variants usually has the t(14; 18) (q32;q21) IGH/BCL2 translocation?

  1. Diffuse follicular lymphoma variant
  2. Duodenal type follicular lymphoma
  3. Pediatric type follicular lymphoma (PTFL)
  4. Primary testicular follicular lymphoma
Board review style answer #1
B. Duodenal type follicular lymphoma

Comment Here

Reference: Duodenal type follicular lymphoma
Board review style question #2
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    54 year old man presents with a dyspepsia. In his upper endoscopy a small polypoid lesion is detected in duodenum. Part of the immunohistochemical stains are provided in this case (left to right: BCL2, BCL6 and Ki67 immunostains). What is the most probable diagnosis?”

  1. Chronic lymphocytic leukemia / small lymphocytic lymphoma
  2. Follicular lymphoma
  3. Mantle cell lymphoma
  4. Reactive lymphoid follicle in a small intestine polyp
Board review style answer #2
B. Follicular lymphoma

Comment Here

Reference: Duodenal type follicular lymphoma
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