title: Feline gastrointestinal lymphoma: mucosal architecture, immunophenotype, and molecular clonality.
abstract: Gastrointestinal lymphomas were identified in 120 cats between 1995 and 2006. Lymphomas were classified according to the World Health Organization (WHO) scheme. Cats with mucosal T-cell lymphoma (n = 84) predominated and had a median survival of 29 months. Mucosal T-cell lymphoma matched WHO enteropathy-associated T-cell lymphoma (EATCL) type II. Epitheliotropic T-cell infiltrates were present in 62% of cats and occurred as clusters or diffuse infiltrates of small to intermediate-sized T cells in villous and/or crypt epithelium. Similar lymphocytes infiltrated the lamina propria in distinctive patterns. Cats with transmural T-cell lymphoma (n = 19) had a median survival of 1.5 months. Transmural T-cell lymphoma matched WHO EATCL type I. Epitheliotropic T-cell infiltrates were present in 58% of cats. Large lymphocytes (n = 11), mostly with cytoplasmic granules (LGL-granzyme B+) (n = 9) predominated. Transmural extension across the muscularis propria characterized the lesion. Both mucosal and transmural T-cell lymphomas were largely confined to the small intestine, and molecular clonality analysis revealed clonal or oligoclonal rearrangements of T-cell receptor-γ in 90% of cats. Cats with B-cell lymphoma (n = 19) had a median survival of 3.5 months. B-cell lymphomas occurred as transmural lesions in stomach, jejunum, and ileo-cecal-colic junction. The majority were diffuse, large B-cell lymphomas of centroblastic type. In conclusion, T-cell lymphomas characterized by distinctive mucosal architecture, CD3 expression, and clonal expansion predominated in the feline gastrointestinal tract.
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, 4206 VM3A, 1 Shields Ave, University of California, Davis, CA 95616, USA. pfmoore@ucdavis.edu
authors.forename: P F
authors.initials: PF
authors.lastname: Moore
authors.forename: A
authors.initials: A
authors.lastname: Rodriguez-Bertos
authors.forename: P H
authors.initials: PH
authors.lastname: Kass
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000473:pathology*; D002415:Cats; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000473:pathology / Q000662:veterinary*; D016130:Immunophenotyping / Q000662:veterinary*; D008223:Lymphoma / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D008297:Male