A Case of Osseous Metaplasia in a Gastric Hyperplastic Polyp

Abstract

A 63-year-old woman with a history of hypertension, sick sinus syndrome, and Hashimoto’s thyroiditis was referred to our facility for evaluationof amass in segment 8of the liver.Abdominal computed tomography showedanenhancingmass in segment 8measuring 5.8 cm. The liver biopsy showed a moderately differentiated adenocarcinoma, most consistent with intrahepatic cholangiocarcinoma. A screening gastrointestinal endoscopy revealed a 7-mm sessile polyp in the antrum (Figure 1). The polyp showed reddish discoloration with erosive changes on the surface and was removed with a cold snare. No other abnormalities were identified in the stomach. Sections of the polyp showed fragments of antral-type gastric mucosa with foveolar hyperplasia, erosion, acute and chronic inflammation, and focal granulation tissue formation (Figure 2). In addition, multiple foci of woven bone formation without bone marrow surrounding dilated gastric foveolae were identified (Figure 3). No Helicobacter infection, intestinal metaplasia, dysplasia, or malignancy was identified histologically.