Small intestine & ampulla
Benign tumors / tumor-like conditions
Inflammatory fibroid polyp
Author: Hanni Gulwani, M.B.B.S.
Last author update: 1 August 2012
Last staff update: 22 July 2021
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Inflammatory fibroid polyp small bowel
Table of Contents
Definition / general | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosisCite this page: Gulwani H. Inflammatory fibroid polyp. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/smallbowelinflammatoryfibroidpolyp.html. Accessed April 19th, 2024.
Definition / general
- Uncommon, benign polypoid submucosal mass with CD34+ spindle cells and granulation tissue, usually in distal stomach or terminal ileum (Arch Pathol Lab Med 2011;135:1311)
- Presents as obstructive mass or causing intussusception (Radiographics 1999;19:539)
- True neoplasms, usually with PDGFRA mutation (Pathologe 2009;30:117)
Case reports
- 35 year old woman with concurrent appearance of Crohn's disease and inflammatory fibroid polyp (Ann Ital Chir 2005;76:395)
Treatment
- Excision (does not recur)
Gross description
- Polypoid (without stalk), submucosal mass, dumbbell shape in small intestine due to intussuception, mucosal ulceration and splitting and atrophy of muscularis propria
Gross images
Contributed by Claudia Mendez, M.D.
Inflammatory fibroid polyp
Microscopic (histologic) description
- Submucosal mixture of prominent capillaries, spindle cells (occasionally concentrically arranged around vessels / onion skinning) and inflammatory cells (particularly eosinophils, plasma cells and mast cells) in granulation tissue-like stroma (Arch Pathol Lab Med 2010;134:378)
- May be transmural
- May have lymphoid follicles
- Rare multinucleated giant cells, no atypia, no / rare mitotic figures
- Histologic patterns: classical, edematous, fibrovascular, nodular, sclerotic
Microscopic (histologic) images
Contributed by Claudia Mendez, M.D.
4x
10x
40x
Positive stains
Negative stains
- CD117 (although mast cells are positive)
Differential diagnosis
- GIST: malignant in 30 - 50%, plump spindle cells with eosinophilic cytoplasm, variable skenoid fibers and muscular infiltration, CD117+ (Mod Pathol 2000;13:1134, Mod Pathol 2003;16:366)
- Inflammatory myofibroblastic tumor: usually children, may recur, plasma cells and lymphocytes with few eosinophils, mitotic activity in cellular areas, less prominent blood vessels, smooth muscle actin+, desmin+, ALK±, CD34- (Hum Pathol 2002;33:307)
- Inflammatory polyp of Crohn's or ulcerative colitis: similar histology but different clinical history and findings in remainder of bowel
