Hepatosplenic and Hepatocytotropic T-Cell Lymphoma

Abstract

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.

Lymphoma-associated hemophagocytic syndrome in six dogs

“…In the T-cell lymphoma group, six patients were diagnosed with peripheral T-cell lymphoma (PTCL), not otherwise specified (PTCL-NOS); five with systemic anaplastic large cell lymphoma (ALCL); two with subcutaneous panniculitis like T-cell lymphoma (SPTCL); and one with hepatosplenic T-cell lymphoma (HSTL) [ 9 , 12 , 14 , 15 ]. In the previous reports of canine HSTL, erythrophagocytosis by neoplastic lymphocytes and a concurrent hyperplastic population of macrophages were a consistent feature in HSTL [ 4 , 6 , 11 ]. In practice, these macrophages should be termed as not “erythrophagocytes” but rather “hemophagocytes,” because these macrophages include erythrocytes, neutrophils, and platelets.…”

“…The MST for the dogs was 4 days. It has been described that HSTL in dogs most likely originates from CD11d+ splenic red pulp γδ T-cells [ 11 ]. In the present study, half of the cases were interpreted as HSTL, and MST for these dogs was 6 days.…”

Uncommon anatomical sites and anatomopathological presentations of lymphoma in dogs

“…Hepatosplenic lymphoma in both humans and dogs is a rare condition characterized by concomitant involvement of the liver and spleen, in the form of diffuse hepatosplenomegaly, and often of the bone marrow, but with no peripheral nodal involvement (superficial lymphadenopathy) (Weidmann 2000, Keller et al 2012, Swerdlow et al 2017. In this study, this presentation of lymphoma corresponded to 1% of the forms diagnosed in dogs in our routine, similar to what is observed in the veterinary literature, which describes only eight cases in dogs (Fry et al 2003, Cienava et al 2004, Keller et al 2012.…”

“…Hepatosplenic lymphoma in both humans and dogs is a rare condition characterized by concomitant involvement of the liver and spleen, in the form of diffuse hepatosplenomegaly, and often of the bone marrow, but with no peripheral nodal involvement (superficial lymphadenopathy) (Weidmann 2000, Keller et al 2012, Swerdlow et al 2017. In this study, this presentation of lymphoma corresponded to 1% of the forms diagnosed in dogs in our routine, similar to what is observed in the veterinary literature, which describes only eight cases in dogs (Fry et al 2003, Cienava et al 2004, Keller et al 2012. Regarding the affected organs, the case described herein was identical to that observed in the literature, because in seven of the eight reported cases (Cienava et al 2004, Keller et al 2012, hepatosplenic lymphoma was invariably characterized by diffuse hepatosplenomegaly with microscopic involvement of the bone marrow and lungs.…”

Indolent T‐cell‐rich small B‐cell hepatic lymphoma in a Golden Retriever

“…Additionally, multicentric lymphoma, affecting multiple peripheral lymph nodes, is the most common presentation of canine lymphoma . Primary hepatic lymphoma is much less common and tends to have an aggressive clinical course . This report describes a case of indolent small B‐cell lymphoma with marked T‐cell infiltrates, presenting in the liver and intra‐abdominal lymph nodes.…”