@article{oai:asahikawa-med.repo.nii.ac.jp:00005911,
 author = {高橋, 慶太郎 and 藤谷, 幹浩 and 市原, 真 and 盛一, 健太郎 and 奥村, 利勝},
 issue = {23},
 journal = {Medicine},
 month = {Jun},
 note = {PMID：28591047, RATIONALE:
\nGastric adenocarcinoma of fundic gland mucosa type (GA-FGM) is a rare tumor composed of atypical cells with differentiation toward the fundic gland as well as the foveolar epithelium. Including our case, only 9 cases of GA-FGMs were reported from 2010 to 2016.
CONCERNS OF THE PATIENT:
\nAn 87-year-old man was referred to our institution for endoscopic resection of a gastric lesion. The tumor was classified as type 0-I + IIa according to the Paris classification. Magnifying endoscopy with narrow band imaging (ME-NBI) revealed different structures of crypts and vessels among the components, illustrating the collision of 2 types of gastric cancer.
INTERVENTIONS:
\nWe performed endoscopic submucosal dissection and successfully removed the tumor en bloc.
OUTCOMES:
\nThe histological findings differed markedly between the 0-I lesion and the 0-IIa lesion. The superficial part of the 0-I lesion consisted of a papillary structure, and the deeper part consisted of a tubular structure that showed inverted downward growth to the submucosal layer with the lamina muscularis mucosae. Immunohistochemically, the superficial part of the 0-I lesion was positive for MUC5AC, which had differentiated to foveolar epithelium. The deeper part was positive for pepsinogen-I and MUC6, which had differentiated to fundic gland. The 0-I lesion was diagnosed as gastric phenotype of adenocarcinoma differentiated to fundic gland mucosa with upward growth in the superficial part and downward growth in the deeper part. The 0-IIa lesion was composed of a tubular structure positive for MUC2, and it was diagnosed as an intestinal phenotype of well differentiated adenocarcinoma. The boundary was clear, and no transitional tissue was observed between the 0-I and 0-IIa lesions, suggesting that the 0-I + IIa lesion was a gastric collision tumor of GA-FGM and well differentiated adenocarcinoma.
LESSONS:
\nWe herein report the first case of inverted GA-FGM colliding with well differentiated adenocarcinoma. ME-NBI can be used to diagnose GA-FGM even if the lesion collides with other types of adenocarcinoma., This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), text, application/pdf},
 title = {Inverted gastric adenocarcinoma of fundic gland mucosa type colliding with well differentiated adenocarcinoma: A case report},
 volume = {96},
 year = {2017},
 yomi = {タカハシ, ケイタロウ and フジヤ, ミキヒロ and イチハラ, シン and モリイチ, ケンタロウ and オクムラ, トシカツ}
}