Inflammatory Fibroid Polyp of the Gastrointestinal Tract: A Systematic Review for a Benign Tumor

Abstract

Background/aim: Inflammatory fibroid polyp (IFP) is a rare, usually solitary and intraluminal polypoid benign tumor that can affect any part of the gastrointestinal (GI) tract, although in the majority of cases it affects the stomach. This lesion is characterized by proliferation of highly vascular fibrous tissue and infiltration by a variable number of different inflammatory cells. Its etiology is unknown. Our aim was to describe all the reported data concerning IFP.

Materials and methods: An extensive search of the PubMed Index was performed for publications with titles or abstracts containing the terms: "inflammatory fibroid polyp" with/without "Vanek". Results were filtered for publications in English and concerning only humans. One hundred and twenty-four publications were finally included in this review.

Results: IFP has a female predominance. It affects patients in their 5th decade of life, although there are cases of patients from 4 to 84 years of age. IFP usually affects the stomach and more specifically the gastric antrum but can be detected throughout the GI tract. A significant number of cases remain asymptomatic but the most frequent presentations of IFP are abdominal pain, acute abdomen and GI bleeding. Most cases are treated by endoscopic resection of the lesion. No recurrence nor IFP-specific complications have been reported. Histopathology of IFP varies.

Conclusion: It is relatively safe to conclude that both the etiology and the timing of diagnosis might change the histopathology, immunohistological staining and tissue structure of IFP. Suggested theories should be taken into consideration with caution as the etiology and pathophysiological mechanisms of IFP are unknown.

Keywords: Inflammatory; fibroid; gastrointestinal; polyp; review; systematic; tumor; vanek.

Figure 1. PRISMA flow for the current literature review

Figure 2. Macroscopic view of Inflammatory fibroid polyp (IFP). A: Gastroscopy demonstrating a reddish IFP of the antrum. B: Colonoscopy demonstrating a pedunculated and reddish IFP of the cecum. C: Pedunculated IFP of the rectum

Figure 3. Abdominal computed tomography demonstrating an inflammatory fibroid polyp of the lesser curvature of the stomach. A: Coronal section; B: transverse section; C: sagittal section

Figure 4. Endoscopic polypectomy. A: Resection of an inflammatory fibroid polyp of the antrum; B: Resection of an inflammatory fibroid polyp of the cecum

Figure 5. Histological characteristics of inflammatory fibroid polyp (IFP) of the colon (A-C) and stomach (D- I). A: IFP of the colon arising in the submucosa and expanding to the mucosa (hematoxylin-eosin, original magnification ×40). B: IFP of colon consisting of a loose fibromyxoid background, inflammatory cells and variably sized blood vessels (hematoxylin-eosin, original magnification ×100). C: Bland spindle-shaped mesenchymal cells and heavy inflammatory infiltrate consisting mainly of eosinophils and secondarily of lymphocytes and plasma cells (hematoxylineosin, original magnification ×200). D: Submucosal tumor under low-power examination (hematoxylin-eosin, original magnification ×20). E, F: The tumor shows a prominent vasculature, large numbers of inflammatory cells, especially eosinophils, and concentrically arranged polygonal to spindle tumor cells around vessels (hematoxylin-eosin, original magnification ×100 and ×200, respectively). G: Multinucleated tumor cells are rarely seen (hematoxylin-eosin, original magnification ×400). H: Spindle-shaped tumor cells are positive for CD34 but negative for C-KIT (CD34, original magnification x200). I: Scattered mast cells are depicted (C-KIT, original magnification ×200.