title: Helicobacter pylori-negative / API2-MALT1 translocation-negative low-grade MALT lymphoma.
abstract: A 71-year-old man with a Helicobacter pylori infection-negative and API2-MALT1 translocation-negative extranodal marginal-zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type of the stomach has been followed conservatively for over 5 years. The lesion has shown no major morphological changes or malignant progression into a diffuse large-cell type during the time course. The absence of genetic translocation of API2-MALT1 was confirmed with fluorescence in situ hybridization (FISH). The prognosis of H. pylori-negative and API2-MALT1 translocation-negative low-grade MALT lymphoma is unknown, and a standard treatment for such lymphoma has yet to be defined. The case of MALT lymphoma negative for both of the above factors that we report has shown no obvious rapid progression or malignant change over the long-term course. Although curative operation and/or chemoradiotherapy should still be discussed as the treatment of choice, the treatment of this type of lymphoma must be carefully determined on a case-by-case basis, according to its biological status and prognosis.
authors.affiliation: Department of Gastrointestinal Surgery, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nozaki
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Nomura
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Shimizu
authors.forename: Naoki
authors.initials: N
authors.lastname: Hiki
authors.forename: Nao
authors.initials: N
authors.lastname: Yoshizawa
authors.forename: Susumu
authors.initials: S
authors.lastname: Aikou
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kubota
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Hanzo
authors.initials: H
authors.lastname: Kurosaka
authors.forename: Aya
authors.initials: A
authors.lastname: Shinozaki
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Mafune
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukayama
authors.forename: Michio
authors.initials: M
authors.lastname: Kaminishi
mesh_terms: D000368:Aged; D005773:Gastroscopy / Q000379:methods; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis* / Q000378:metabolism / Q000382:microbiology*; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000235:genetics / Q000382:microbiology; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000382:microbiology; D014178:Translocation, Genetic
chemical_list: C415943:API2-MALT1 fusion protein, human; D015514:Oncogene Proteins, Fusion