Rare case of gastric inflammatory fibroid polyp located at the fornix of the stomach and mimicking gastric cancer: a case report.

BACKGROUND: Gastric inflammatory fibroid polyp (IFP) is a rare polypoid lesion of the stomach that is characterized pathologically by the presence of spindle cells, a prominent network of blood vessels, and inflammatory infiltration of eosinophils. IFP is mainly located in the gastric antrum and is usually semi-pedunculated and covered with normal mucosa. There have been several reports of large IFPs with ulceration on the surface, at the apex, but no report of the IFP with ulceration at the fornix of the stomach. We report a case of IFP with ulceration that was suggested to be gastric cancer and was resected for diagnostic treatment. CASE PRESENTATION: A 79-year-old woman presented to our hospital. During mass screening for cancer, stomach fluoroscopy revealed an abnormal shadow. Endoscopy showed an ulcerated tumor at the fornix of stomach; hence, gastric cancer was suggested because of the polypoid lesion with irregular ridges and ulceration. Pathological diagnosis of gastric biopsy specimens revealed an inflammation of the gastric mucosa, and specific findings for gastric cancer were not obtained. Because we could not exclude gastric malignancies such as cancer or gastrointestinal stromal tumor, we performed a partial resection of the stomach with a 2-cm margin using the laparoscopic-assisted method. Pathological examination of the resected specimen revealed that the tumor was present in the submucosal layer and consisted of collagen fiber containing inflammatory cell infiltration of mainly eosinophils. A prominent network of blood vessels was also found in the specimens. Immunohistochemical staining revealed mild positivity for CD34, and α-SMA and was negative for c-kit, DOG-1, s-100, desmin, ALK, and IgG4. The lesion was thus diagnosed as an IFP. The postoperative course was uneventful. The patient is currently asymptomatic and has shown no recurrence. CONCLUSION: IFPs have variable locational, morphological, histological, pathological, and immunohistochemical features. We reported that the gastric IFP was located at the fornix of the stomach and was similar in morphology to gastric cancer. This case is clinically significant to avoid over-surgery.