Table of ContentsDefinition / general | Essential features | Terminology | Sites | Etiology | Clinical features | Case reports | Treatment | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1
Cite this page: Assarzadega N, Gonzalez RS. Inflammatory fibroid polyp. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stomachinflammatoryfibroid.html. Accessed January 18th, 2021.
Definition / general
- Benign neoplastic polyp that occurs anywhere in gastrointestinal tract but most commonly in stomach and small intestine
- Benign mesenchymal gastrointestinal polyp that arises in the submucosa
- Associated with PDGFRA mutation
- Also known as Vaněk polyps (Am J Pathol 1949;25:397)
- Formerly called eosinophilic granuloma
- Usually arises in pylorus or distal antrum in stomach
- May be familial (Devon polyposis syndrome, Gut 1992;33:1004)
- Peak incidence in sixth or seventh decade of life
- No endoscopic surveillance is required after the histological diagnosis is confirmed
- Rarely associated with adenocarcinoma or adenoma (Arch Pathol Lab Med 1988;112:829)
- 79 year old woman with chronic gastritis and a 2 cm sessile gastric polyp (Case #421)
- Local excision
- Typically solitary, small and sessile
- Median size 1.5 cm but can measure up to 9 cm
Microscopic (histologic) description
- Submucosal lersion composed of spindle and stellate stromal cells
- Loose edematous stroma containing thin walled blood vessels with characteristic onion skin arrangement of spindled cells around vessels
- Inflammatory infiltrate rich in eosinophils
- Can infiltrate lamina propria
- Minimal mitotic activity
Microscopic (histologic) images
Contributed by Naziheh Assarzadegan, M.D.
Molecular / cytogenetics description
- Associated with activating mutation in the platelet derived growth factor receptor alpha (PDGFRA) gene, supporting a neoplastic origin (Histopathology 2012;61:59)
Sample pathology report
- Stomach, antrum, polypectomy:
- Inflammatory fibroid polyp (3.1 cm), focally extending to deep margin (see comment)
- Lateral margins unremarkable.
- Comment: An immunohistochemical stain for CD34 is positive.
Board review style question #1
Which of the following statements is true about inflammatory fibroid polyps?
- They are associated with activating mutation in the platelet derived growth factor receptor alpha gene
- They are benign and nonneoplastic
- They are synonymous with inflammatory polyps
- They are typically centered on the muscularis propria