Hepatosplenic and hepatocytotropic T-cell lymphoma: two distinct types of T-cell lymphoma in dogs.
The clinical, clinicopathologic, and pathological findings of 9 dogs with T-cell lymphoma that involved the liver in the absence of peripheral lymphadenopathy were assessed. Seven dogs had hepatosplenic T-cell lymphoma (HS-TCL). Dogs with HS-TCL presented with hepato- and/or splenomegaly, regenerative anemia, thrombocytopenia, and hypoproteinemia. The clinical course was rapidly progressive with all dogs but 1 dead within 24 days of initial presentation. Neoplastic lymphocytes were centered on hepatic and splenic sinusoids and had a CD3+ (5/7), TCRαβ- (5/5), TCRγδ+ (3/5), CD11d+ (6/7), granzyme B+ (5/7) immunophenotype. Bone marrow and lungs were consistently but variably involved. These findings closely resemble the human disease and support the classification of HS-TCL as a distinct World Health Organization entity in dogs. The remaining 2 dogs markedly differed in the pattern of hepatic involvement by neoplastic lymphocytes, which were not confined to hepatic sinusoids but invaded hepatic cords. In addition, neoplastic cells had a CD11d- immunophenotype, and clinicopathologic data indicated marked cholestasis and mild to absent anemia. Based on the distinct tropism of neoplastic lymphocytes for hepatocytes, the name hepatocytotropic T-cell lymphoma (HC-TCL) is proposed. Given the histomorphologic, clinicopathologic, and immunophenotypic differences, HC-TCL likely represents a separate biological entity rather than a histomorphologic variant of HS-TCL.
Department of Pathology, Microbiology and Immunology School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
S M
SM
Keller
W
W
Vernau
J
J
Hodges
P H
PH
Kass
J G
JG
Vilches-Moure
V
V
McElliot
P F
PF
Moore
D000818:Animals; D000911:Antibodies, Monoclonal; D004283:Dog Diseases / Q000145:classification* / Q000473:pathology*; D004285:Dogs; D005434:Flow Cytometry / Q000662:veterinary; D022781:Hepatocytes / Q000473:pathology*; D007150:Immunohistochemistry / Q000662:veterinary; D016130:Immunophenotyping / Q000662:veterinary; D008113:Liver Neoplasms / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D016399:Lymphoma, T-Cell / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D008854:Microscopy, Electron / Q000662:veterinary; D013160:Splenic Neoplasms / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D018709:Statistics, Nonparametric
D000911:Antibodies, Monoclonal