Gastric inverted hyperplastic polyp with typical endoscopic feature

A 37-year-old woman received gastroscopy for compliant of upper abdominal discomfort for six months. A polyp with size in 10 mm was found in the upper third of stomach. The polyp with a papilla-like depression in the top and smooth surface similar to surrounding non-atrophic mucosal characterized by regular arrangement of collective veins (Fig. 1A and B). Endoscopic ultrasound showed the lesion was hypo –equal echo in the mucosal layer, displayed expansive growth nature and oppressing submucosal layer (Fig. 1C). Histology of biopsy showed inflamed mucosa with submucosal atypic oxyntic gland, considering histological diagnosis of ectopic gastric glands with atypia, but adenocarcinoma of fundic gland type cannot be ruled out (Fig. 1D and E). Thus, the polyp was removed by endoscopic submucosal dissection for accurate histological diagnosis. The histology showed the benign hyperplastic glands with inverted growth manner with communication with mucosal at the top, the surround area was covered by normal oxyntic mucosa (Fig. 2), and diagnosed as gastric inverted hyperplastic polyp (GIHP). GIHPs are rare gastric polyps and typically appeared as rounded subepithelial lesions with normal overlying mucosa, more than half of cases with surface erosion, depression, or orifice exuding mucin [ ]. GIHPs had the potential to develop adenocarcinoma, but histological diagnosis based on biopsy is challenging, endoscopic resection may be a wise choice for accurate diagnosis.