Pyloric Gland Adenoma of the Stomach – A Clinicopathologic Study of 8 Cases
IG Do, KM Kim, CK Park. Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
Background: Pyloric gland adenoma (PGA) is a rarely described neoplasia of stomach accounting for 2.7% of all gastric polyps. Similar adenomas of the gastric type have been reported in gastric heterotopic mucosa in the duodenum, gallbladder, main pancreatic duct, and uterine cervix. Apart from case reports, only a few clinical follow-up data are available on PGA in the stomach and their relationship to malignant transformation was not fully explored.
Design: In a large comprehensive cancer center located in a gastric cancer prevalent area, 8 PGAs from 8 patients were retrieved. Clinicopathologic features and immunohistochemical panel consisting of mucin core peptides (MUC) 2, MUC6, MUC5AC and CD10 were studied. Clinical follow-up information was obtained in 4 cases of PGA. PGAs were divided into 3 categories: those with low-grade dysplasia, those with high-grade dysplasia, and those in association with adenocarcinoma.
Results: The mean age of PGAs was 62 years with a male predominance over female by 7: 1. The locations within the stomach were cardia (n=3), fundus (n=3), high body (n=1) and lower body (n=1). Microscopically, all 8 cases were classified as 5 PGAs with low-grade dysplasia, 1 PGA with high-grade dysplasia, and 2 PGAs in association with adenocarcinoma. PGAs were mainly composed of closely packed pyloric type glands with monolayer of cuboidal or columnar cells containing round nuclei and pale to eosinophilic cytoplasm and forming some ectactic foveolae. Immunohistochemically, all PGAs were strongly positive for MUC 6 and negative for MUC 5AC, MUC 2 and CD10. Interestingly, two PGAs showed continuous transition to well differentiated gastric-type adenocarcinoma at the time of diagnosis and one PGA with high-grade dysplasia progressed to invasive tubular adenocarcinoma during the follow-up.
Conclusions: PGAs have a characteristic histologic appearance and mucin phenotype. In our experience, 37.5% of gastric PGAs showed transition or progression to adenocarcinoma. PGAs are true neoplasms with a high potential for malignant transformation and require complete removal and close clinical follow-up.
Monday, March 22, 2010 1:00 PM
Poster Session II # 75, Monday Afternoon