title: Localized amyloidosis and gastrointestinal lymphoma: a rare association.
abstract: OBJECTIVE
  Five cases of primary gastrointestinal (GI) lymphoma (three in the stomach, one in the ileum (IPSID) and one in the colon) associated with localized AL amyloidosis were studied to identify morphological or immunohistochemical features which could explain the amyloid deposition.
  
  
  RESULTS
  All the cases were low-grade marginal zone B-cell lymphomas; one case of gastric lymphoma and the IPSID also had a high-grade component. The lymphomas had a monoclonal plasma cell population, with different light and heavy-chain type expression in the five cases. Plasma cell differentiation was closely associated with the amyloid deposits. The latter were an incidental microscopic finding in one case, but produced tumoral masses in the other.
  
  
  CONCLUSIONS
  The presence of amyloid in primary GI lymphoma is rare, but can have diagnostic value. In the present study, neither particular features of the lymphomatous proliferation nor specific agents are identified. Therefore, the factors predisposing to amyloid deposition require elucidation.
authors.affiliation: Institute of Pathological Anatomy and Histopathology, University of Ancona, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Goteri
authors.forename: R
authors.initials: R
authors.lastname: Ranaldi
authors.forename: S A
authors.initials: SA
authors.lastname: Pileri
authors.forename: I
authors.initials: I
authors.lastname: Bearzi
mesh_terms: D000368:Aged; D000686:Amyloidosis / Q000150:complications* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism; D005767:Gastrointestinal Diseases / Q000150:complications* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005770:Gastrointestinal Neoplasms / Q000150:complications* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000378:metabolism; D007146:Immunoglobulin lambda-Chains / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D016131:Lymphocyte Subsets; D008223:Lymphoma / Q000150:complications* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D012333:RNA, Messenger