GNAS-mutated carcinoma arising from gastric foveolar metaplasia in the duodenum after 9 years of observation

Yasumasa Matsuo, Hiroyuki Yamamoto, Yoshinori Sato, Ritsuko Oikawa, Tadateru Maehata, Takashi Fujino, Naohisa Yahagi, Hiroshi Yasuda, Masayuki Takagi, Fumio Itoh

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


This case involved an 80-year-old man. Screening with esophagogastroduodenoscopy (EGD) in 2004 revealed Brunner’s gland hyperplasia (BGH), 5 mm in size, in the duodenal bulb. The size of the lesion increased and its shape has changed since then, as detected in subsequent EGDs. The lesion had increased in size to 15 mm with a depression and biopsy specimens revealed an adenocarcinoma. The patient underwent endoscopic mucosal resection. Histopathological assessments indicated an adenocarcinoma arising from gastric foveolar metaplasia (GFM) adjacent to BGH. BGH stained positive for MUC6, and GFM and the adenocarcinoma stained positive for MUC5AC. Mutations of the GNAS gene were not detected in the GFM biopsied in 2007. On the other hand, common GNAS mutations (R201H) were detected in GFM and the adenocarcinoma in the endoscopically resected specimen in 2013. Moreover, mutant allele frequencies were higher in the carcinoma than in GFM. The patient remains disease-free for 4 years after endoscopic treatment. This case report further supports the notion that GFM may be a precursor lesion in the process of GNAS-mutated, gastric-type duodenal carcinogenesis.

Original languageEnglish
Pages (from-to)391-395
Number of pages5
JournalClinical journal of gastroenterology
Issue number5
Publication statusPublished - 2018 Oct 1


  • GNAS mutation
  • Gastric foveolar metaplasia
  • Gastric-type duodenal cancer
  • MUC5AC
  • Pyrosequencing

ASJC Scopus subject areas

  • Gastroenterology


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