Can the stomach be a target of cap polyposis?

A 67-year-old woman presented with epigastric pain and nausea. Gastroscopy showed multiple, variable-sized nodules on the posterior wall and lesser curvature of the upper body of the stomach. Grossly, the lesions resembled sessile or semi-pedunculated polyps, and on closer look, they showed central ulceration with a thick mucoid or fibropurulent exudate ([Fig. 1]).

Fig. 1 a, b Gastroscopic view of the stomach showing multiple, variable-sized polyps on the posterior wall and lesser curvature of the upper body, as well as multiple, small, irregular nodular lesions all over the upper part of the gastric mucosa. c Gastroscopic view of the lesions showing sessile polyps with central ulceration and a thick mucoid exudative cap.

To confirm the diagnosis, we performed endoscopic mucosal resection and removed one lesion. The Campylobacter-like organism (CLO) test was positive. Microscopic examination of the gastric polyp showed irregular proliferation of crypts accompanied by chronic inflammation. The surface of the polyp was eroded and covered by granulation tissue and acute inflammatory exudates ([Fig. 2]).

Fig. 2 a Photomicrograph of a gastric polyp showing irregular proliferation of crypts and chronic inflammation (hematoxylin and eosin [H&E], magnification × 12.5). b Higher power view of the polypoid lesion showing the eroded surface covered with granulation tissue and acute inflammatory exudates (H&E, magnification × 200).

Colonoscopic findings were unremarkable. The patient was given Helicobacter pylori eradication treatment. Four months after H. pylori eradication, gastroscopy was carried out again. Multiple, sessile or semi-pedunculated polyps were still noted on the upper body of the stomach but the size of the lesions had decreased slightly ([Fig. 3]).

Fig. 3 Gastroscopic view of stomach 4 months after Helicobacter pylori eradication, showing multiple, sessile polyps, slightly smaller than before and covered with mucoid caps.

The rapid urease test was negative. The patient attended our hospital again 16 months after H. pylori eradication. She denied having abdominal pain, nausea, or vomiting. On gastroscopy, the lesions described above were no longer seen ([Fig. 4]).

Fig. 4 Gastroscopic view of stomach 16 months after Helicobacter pylori eradication showing no mucosal abnormality.

The CLO test was negative.

Cap polyposis, first described by William and Morson in 1985, is a rare disease with unique clinicopathologic features [1]. It commonly affects the sigmoid colon and rectal mucosa [2]. The characteristic endoscopic feature is the presence of multiple, sessile polyps covered by an apical “cap” consisting of mucoid and fibropurulent exudates [3]. Recently, Oiya et al. reported a case of colonic cap polyposis with similar lesions in the stomach [4]. After H. pylori eradication treatment, all colonic and gastric lesions were healed [4] [5].

Here, we report a case of gastric cap polyposis with no evidence of colonic lesions, cured by H. pylori eradication treatment. H. pylori eradication treatment may be beneficial in patients with gastric cap polyposis, avoiding the need for endoscopic or surgical intervention.

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References

• 1 William GT BH, Morson B C. Inflammatory “cap” polyps of the large intestine [abstract].  Br J Surg. 1985;  72 Suppl 133
• 2 Esaki M, Matsumoto T, Kobayashi H. et al . Cap polyposis of the colon and rectum: an analysis of endoscopic findings.  Endoscopy. 2001;  33 262-266
• 3 Campbell A P, Cobb C A, Chapman R W. et al . Cap polyposis – an unusual cause of diarrhoea.  Gut. 1993;  34 562-564
• 4 Oiya H, Okawa K, Aoki T. et al . Cap polyposis cured by Helicobacter pylori eradication therapy.  J Gastroenterol. 2002;  37 463-466
• 5 Akamatsu T, Nakamura N, Kawamura Y. et al . Possible relationship between Helicobacter pylori infection and cap polyposis of the colon.  Helicobacter. 2004;  9 651-656