title: Gastric adenocarcinoma with chief cell differentiation.
abstract: A case of adenocarcinoma with chief cell differentiation, a novel entity in the stomach, is presented. An 82-year-old woman who had undergone distal gastrectomy, was scheduled for upper gastrointestinal endoscopy to clarify mechanical ileus. A protruding tumor 16 x 14 x 9 mm in size was found in the cardia of the remnant stomach. Histological examination indicated a well-differentiated tubular adenocarcinoma composed of basophilic columnar or cuboidal cells with occasional coarse eosinophilic granules. Immunohistochemical analysis revealed strong expression of pepsinogens I and II and Runt-related transcription factor gene 3 (RUNX3), characteristic for chief cells, and MUC6 typical for mucous neck cells. However, the tumor cells were negative for the proton pump alpha subunit, a marker for parietal cells. Cdx2 and defensin-5 were not present, confirming the lack of an intestinal phenotype. The cancer cells shared characteristics of a chief cell and a mucous neck cell, resembling an ancestor of these two cell types, so-called 'primitive chief cell' in fundic gland. In line with these data, the cancer was diagnosed as an adenocarcinoma with chief cell differentiation.
authors.affiliation: Division of Oncological Pathology, Aichi Cancer Center Research Institute, Aichi Cancer Center Hospital, Nagoya, Japan. ttsukamt@aichi-cc.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tsukamoto
authors.forename: Takio
authors.initials: T
authors.lastname: Yokoi
authors.forename: Shinya
authors.initials: S
authors.lastname: Maruta
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kitamura
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Hisayo
authors.initials: H
authors.lastname: Ban
authors.forename: Masae
authors.initials: M
authors.lastname: Tatematsu
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D002299:Cardia / Q000473:pathology; D019872:Chief Cells, Gastric / Q000737:chemistry / Q000473:pathology*; D005260:Female; D006801:Humans; D013274:Stomach Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor