title: [A case of a collision tumor comprising mucosa-associated lymphoid tissue lymphoma and early gastric cancer].
abstract: A 60-year-old woman underwent upper gastrointestinal endoscopy for an abnormality identified during routine examination. The lower gastric corpus showed a type 0-I elevated lesion with a faded mucosa and an area of converging mucosal folds in contact with the lesion. Biopsy indicated the former to be a high-grade adenoma and the latter to be a mucosa-associated lymphoid tissue (MALT) lymphoma. At the same time, Helicobacter pylori infection was diagnosed. Eradication therapy was administered to manage the MALT lymphoma; this resulted in improvement after 3 months. Endoscopic submucosal dissection was performed for the elevated lesion, and subsequent histopathology showed contact between the MALT lymphoma and gastric cancer. Therefore, the patient was diagnosed with a collision tumor. Concurrent cancers are increasingly reported and should be considered during examination.
authors.affiliation: Department of Gastroenterology, Otaru Municipal Hospital.
authors.forename: Mai
authors.initials: M
authors.lastname: Isosaka
authors.forename: Takeya
authors.initials: T
authors.lastname: Adachi
authors.forename: Tomoya
authors.initials: T
authors.lastname: Iida
authors.forename: Kei
authors.initials: K
authors.lastname: Mitsuhashi
authors.forename: Michihiro
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kondou
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Tokuma
authors.initials: T
authors.lastname: Tanuma
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kasai
mesh_terms: D000236:Adenoma / Q000473:pathology*; D005260:Female; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000473:pathology*; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D013272:Stomach Diseases / Q000150:complications; D013274:Stomach Neoplasms / Q000473:pathology*