Pyloric Gland Adenoma

Pyloric gland adenoma (PGA) of Gallbladder: PGAs have a lobular architecture and consist of tightly packed, round, oval or irregularly shaped glands. They are lined by bland gastric pyloric-type or Brunner gland-like mucinous epithelium with abundant apical mucinous cytoplasm and small, peripherally located low-grade nuclei. Paneth cells and neuroendocrine cells may be present. High-grade dysplasia and even invasive carcinoma may be occasionally seen with larger lesions (> 1 cm). The molecular pathogenesis of PGAs is different from that of gallbladder carcinomas. They lack TP53 and CDKN2A mutations and instead harbor CTNNB1 mutations.

Image courtesy of: Dr. Ibrahim Zardawi; used with permission.