title: A case with primary gastric lymphoma producing IgM and IgG immunoglobulins.
abstract: We describe a primary gastric lymphoma with IgM kappa and IgG kappa types of immunoglobulin in the neoplastic cells. The neoplastic cells containing IgM were morphologically different from those containing IgG. The IgG-bearing cells had globular cytoplasmic inclusions, but IgM-bearing cells did not. The neoplastic cells had two Ig heavy-chain gene rearrangements, with a germline band and a single kappa light-chain gene rearrangement. Immunoglobulin expression with light-chain restriction of the neoplastic cells and single light-chain gene rearrangement indicated that the morphologically different neoplastic cells were derived from a common progenitor. The expression of IgM and IgG and two rearrangement bands of immunoglobulin heavy-chain gene suggested that class switching might have occurred in the lymphoma cells.
authors.affiliation: First Department of Pathology, Nagoya University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Yatabe
authors.forename: N
authors.initials: N
authors.lastname: Mori
authors.forename: K
authors.initials: K
authors.lastname: Oka
authors.forename: J
authors.initials: J
authors.lastname: Asai
mesh_terms: D000368:Aged; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D006801:Humans; D017578:Immunoglobulin Class Switching; D007074:Immunoglobulin G / Q000032:analysis* / Q000235:genetics; D007075:Immunoglobulin M / Q000032:analysis* / Q000235:genetics; D008223:Lymphoma / Q000276:immunology* / Q000473:pathology; D008297:Male; D013274:Stomach Neoplasms / Q000276:immunology* / Q000473:pathology
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M