title: Analysis of immunoglobulin light-chain mRNA in gastric malignant lymphoma using new highly sensitive in situ hybridization method.
abstract: BACKGROUND: To analyze B-cell monoclonality, we need fresh materials for the Southern blotting method. In situ hybridization (ISH) for the detection of immunoglobulin light-chain mRNA can be used in formalin-fixed and paraffin-embedded tissues. However, it is difficult to detect low levels of mRNA copies. So we must develop new highly sensitive in situ hybridization methods to diagnose gastric malignant lymphoma.METHODS: We analyzed materials from 15 patients with gastric malignant lymphoma, using a new highly sensitive ISH method, and compared the results with those of a conventional method.RESULTS: With this new method, 13 of 15 cases were shown to have monotypic cytoplasmic signals, and monoclonality was detected in 3 of 4 cases of mucosa-associated lymphoid tissue (MALT) lymphoma.CONCLUSIONS: The accuracy of endoscopic biopsies is not satisfactory. However, the detection of immunoglobulin light chain mRNA, using the new highly sensitive ISH method with a non-radioactive isotope oligonucleotide probe, can be used to diagnose gastric malignant lymphoma even when conventional immunoglobulin light-chain mRNA or proteins alone cannot demonstrate the clonality.
authors.affiliation: Second Department of Surgery, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sumiyoshi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Takafumi
authors.initials: T
authors.lastname: Maekawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shirakusa