Pyloric Gland Adenoma

Comments:
Pyloric gland adenoma (PGA) of Gallbladder: Immunohistochemically, PGAs are positive for CK7 and MUC6. The differential diagnosis is with pyloric gland metaplasia which may sometimes acquire exuberant polypoid configuration. Pyloric metaplasia is usually microscopic and does not produce a mass lesion. It consists of variably sized glands with intervening stroma. WHO 2019 classification recommends that pyloric gland nodules < 0.5 cm and seen in a background of pyloric gland metaplasia should not be called PGAs. PGAs are cured by cholecystectomy if there is no invasive carcinoma.

This high magnification view of a PGA shows tightly packed glands lined by bland mucinous epithelium with low-grade nuclei. Note the lining of biliary epithelium on the right. Image courtesy of: Dr. Ibrahim Zardawi; used with permission.