Gastric pyloric gland adenoma.

Pyloric gland adenomas are rare neoplasms of the gastrointestinal tract. Gastric pyloric gland adenomas have been shown to arise in chronically damaged mucosa. The neoplastic glands have gastric pyloric gland differentiation and have a tightly packed organization with occasional cystic dilatation. The individual cells are cuboidal to columnar, with eosinophilic to amphophilic cytoplasm and either no apical mucin cap or a poorly formed apical mucin cap. The nuclei are round to oval, with occasional prominent nucleoli. Immunohistochemically, the neoplastic cells label with markers of gastric pyloric gland differentiation, including MUC6 and MUC5AC. There is limited information regarding the natural history of pyloric gland adenomas, but clinical series have described adenocarcinomas in association with gastric pyloric gland adenomas. The ideal clinical management is adequate sampling of the lesion to investigate for high-grade dysplasia and/or invasive cancer and recommendation to clinical colleagues to investigate the background mucosa for the etiology of chronic gastritis as well as potential additional neoplastic lesions. This review will focus on gastric pyloric gland adenomas.