title: Malignant transformation of Nakamura type IV gastric polyp with CA 19-9 production.
abstract: In a 68-year-old Japanese man, a gastric polyp 24mm in diameter with a stalk 15 mm in diameter was diagnosed as well differentiated adenocarcinoma and treated by endoscopic polypectomy. Histologically, most of the resected tissue was adenoma, and atypical cells were papillarily proliferating to form adenocarcinoma in adenoma, a Nakamura type IV gastric polyp. Infiltration of carcinoma was limited to within the mucosal layer. Immunohistochemical study with anti-CA19-9 antibody revealed positive staining in carcinoma cells. Serum CA19-9 level, which showed slight elevation, returned to the normal range 1 month after the polypectomy. The proliferating cell nuclear antigen (PCNA) labeling index and DNA ploidy pattern were analyzed in the resected tissue. The PCNA labeling index was 30% in carcinoma, 17% in adenoma, and 0.1% in the normal tissue. The DNA ploidy pattern was diploid in adenoma and aneuploid in adenocarcinoma. These findings suggest that gastric adenoma, as well as colonic adenoma, may have the potential for malignant transformation.
authors.affiliation: Department of Internal Medicine, Saiseikai Yokohama-shi Nanbu Hospital, Yokohama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nagai
authors.forename: K
authors.initials: K
authors.lastname: Ishii
authors.forename: K
authors.initials: K
authors.lastname: Matsumaru
authors.forename: T
authors.initials: T
authors.lastname: Kohra
authors.forename: T
authors.initials: T
authors.lastname: Okajima
authors.forename: W
authors.initials: W
authors.lastname: Yamamuro
authors.forename: T
authors.initials: T
authors.lastname: Hatori
authors.forename: M
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Sumino
authors.forename: H
authors.initials: H
authors.lastname: Nonaka
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology*; D000236:Adenoma / Q000276:immunology / Q000473:pathology*; D000368:Aged; D018395:CA-19-9 Antigen / Q000096:biosynthesis*; D002471:Cell Transformation, Neoplastic; D006801:Humans; D008297:Male; D011003:Ploidies; D011127:Polyps / Q000276:immunology / Q000473:pathology*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D013274:Stomach Neoplasms / Q000276:immunology / Q000473:pathology*
chemical_list: D018395:CA-19-9 Antigen; D018809:Proliferating Cell Nuclear Antigen