Management of Gastric Polyps

An Endoscopy-Based Approach

Yasser H. Shaib; Massimo Rugge; David Y. Graham; Robert M. Genta

Disclosures

Clin Gastroenterol Hepatol. 2013;11(11):1374-1384. 

In This Article

Inflammatory Fibroid Polyps

Inflammatory fibroid polyps (also known as Vanek tumors) are extremely rare lesions that represent less than 0.1% of all gastric polyps.[62] Endoscopically, they are usually firm, solitary, sessile or pedunculated, and often ulcerated (Figure 6). The histologic features of these polyps are distinctive: they consist of submucosal proliferations of spindle cells, small vessels, and a conspicuous inflammatory infiltrate with a predominance of eosinophils. Hence, these polyps are occasionally (and inaccurately) referred to as eosinophilic granulomas. The adjacent mucosa usually is unremarkable. The pathogenesis of these lesions is unknown, although a familial tendency has been documented in one family.[63] Immunohistochemical staining suggests these polyps have a dendritic cell origin.[64] A recent study found that 70% of inflammatory fibroid polyps contain gain-of-function mutations in the platelet-derived growth factor receptor α polypeptide gene, similar to those found in CD117-negative GISTs, suggesting the possibility of a neoplastic process.[65]

Figure 6.

Inflammatory fibroid polyp. (A) Endoscopic view of an inflammatory fibroid polyp in the antrum showing a firm, well-circumscribed submucosal lesion. (B) Histologically, a flattened, often eroded, gastric epithelium lines a compact aggregate of fibrous tissue mixed with inflammatory cells. (C) Vessels usually are surrounded by a characteristic circumferential deposition of fibroblasts (onion skin), and the stroma contains myriad eosinophils.

Clinical Approach

Most inflammatory fibroid polyps are asymptomatic, but larger polyps have been reported to cause abdominal pain, early satiety, anemia, and gastric outlet obstruction.[66] The endoscopic ultrasound appearance, characterized by an indistinct margin, a hypoechoic homogeneous lesion, and location within the second or third layer with an intact fourth layer, may be helpful in establishing the diagnosis.[67,68,69]

Histopathologic Diagnostic Tips: Special Stains, Immunohistochemistry, and Molecular Studies

Because fibroepithelial polyps are extremely rare, general pathologists may spend their entire career without ever seeing (or at least recognizing) one. However, once familiar with their unique morphology they can be diagnosed instantly (Figure 6). Immunohistochemical staining for CD31 (an endothelial marker) is strongly positive, but it is almost never necessary for the diagnosis and should be used only as a teaching tool.

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