Hepatosplenic αβ T cell lymphoma

Hepatosplenic Alpha-Beta T-Cell Lymphoma: A Challenging Diagnostic Entity

Hepatosplenic T-cell lymphoma (HSTCL) is rare and clinically very aggressive T-cell lymphoma. The majority of cases harbor γδ T-cell receptors (TCRs); however, in some even rarer cases, tumor cells harbor αβ TCR. Recent studies suggest that αβ cases may have distinct morphological characteristics and demonstrate an even more aggressive course. In this case report, we demonstrated that in line with previous findings, αβ case of HSTCL had hemolytic presentation, demonstrated a very aggressive clinical course, and was unrelated to immunosuppression. Morphologically, tumor cells demonstrated diffuse growth pattern, blastoid morphology, and were CD8+ positive on the background of CD4+ small to medium reactive T cells. Additionally, the liver tumor cells demonstrated periportal localization, and in bone marrow, evidence of emperipolesis was noted. The latter finding may significantly contribute to pancytopenia characteristic, all types of HSTCL. Those unusual morphologic and clinical characteristics make diagnosis of this rare subtype of rare disease very challenging. More case analysis is required to establish whether αβ/γδ HSTCL are prognostically or morphologically significantly distinct entities.

Hepatosplenic αβ T-Cell Lymphoma as Second Malignancy in Young Adult Patient With Previously Undiagnosed Ataxia-Telangiectasia

Ataxia-telangiectasia is a rare autosomal recessive neurodegenerative disease characterized by ataxia, radiosensitivity, telangiectases, and increased risk for hematologic malignancies. We present a case of a female individual diagnosed with T-cell acute lymphocytic leukemia at 13 years and subsequently with αβ subtype of hepatosplenic T-cell lymphoma (HSTCL) at 20 years. During her diagnostic work up for HSTCL, paired tumor-germline sequencing identified a diagnosis of ataxia-telangiectasia. We also describe a very refractory clinical course of her αβ HSTCL, including only a brief response to multiagent chemotherapy and an allogenic bone marrow transplant.

An Unusual Case of Hepatosplenic αβ T-Cell Lymphoma Presenting with Coombs'-Negative Hemolytic Anemia

Hepatosplenic T-cell lymphoma (HSTCL) is a rare and aggressive extranodal T-cell lymphoma that comprises <5% of peripheral T-cell lymphomas. The majority of cases harbor the γδ T-cell receptor (TCR), but recently, a few cases have been shown to express the αβ TCR. Comparison of these two subtypes (αβ and γδ) shows similar clinicopathologic and cytogenetic features; however, due to the paucity of reported cases, it is not clear whether they are prognostically distinct entities. We report a case of αβ HSTCL with a rather unusual presentation of Coombs’-negative hemolytic anemia. Diagnosis proved challenging due to an unusual blastoid morphology with the absence of typical intrasinusoidal distribution of tumor cells in the bone marrow. This unique case adds to the growing list of this rare subtype of T-cell lymphomas, which warrant urgent attention due to the lack of effective treatment options and dismal prognosis.

Challenges and new prospects in hepatosplenic γδ T-cell lymphoma

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoid neoplasms characterized by aggressive clinical behavior and dismal prognosis. Hepatosplenic γδ T-cell lymphoma (γδ-HSTL) is a particular form of PTCL that arises from a small subset of γ/δ T-cell receptor-expressing lymphocytes. γδ-HSTL has a rapidly progressive course and poor outcome due also to its refractoriness to conventional chemotherapy regimens. The very low incidence of γδ-HSTL, along with its propensity to mimic different pathological entities, makes this lymphoma a true diagnostic challenge. In this review, we highlight the biological and clinical features of γδ-HSTL that contribute to making this lymphoma a mostly incurable disease. Moreover, we provide a new insight into the crosstalk between HSTL clones and the bone marrow, liver and spleen vascular microenvironment, in which neoplastic cells reside and proliferate. We further discuss γδ-HSTL associated molecules that might be proposed as potential targets for novel therapeutic approaches.

Hepatosplenic alpha/beta T-cell lymphoma masquerading as cirrhosis

A 59-year-old man with diabetes mellitus, prior hepatitis B infection and recently diagnosed cirrhosis with prior Babesiosis presented to our institution from an outside hospital with six months of worsening abdominal pain, myalgias and fevers. On admission, physical examination revealed jaundice, hepatosplenomegaly and diffuse lymphadenopathy. Laboratory investigations demonstrated mild anemia, thrombocytopenia, hyperbilirubinemia and elevated lactate dehydrogenase. Tests for human immunodeficiency virus, and active Babesia microti infection were negative, however Epstein-Barr virus DNA by quantitative PCR was markedly elevated. CT scan revealed features suggestive of a cirrhotic liver without focal mass lesions as well as massive splenomegaly with axillary, retroperitoneal and inguinal lymphadenopathy. Bone marrow and lymph node biopsies were obtained which ultimately revealed hepatosplenic T-cell lymphoma. The patient's initial liver biopsy from five months prior to presentation was re-evaluated by our institution's pathologists. Histologic analysis showed hepatic sinusoidal and portal infiltration of atypical lymphocytes morphologically identical to those present on the more recently excised lymph node tissue. The hepatic sinusoidal lymphoid cells were strongly positive for CD2, CD3 and CD5 whereas CD4, CD8 stained only minor subsets of the T cells. Subsequent flow cytometric immunophenotypying of peripheral blood identified T-cell receptor alpha/beta positive cells that lacked CD4 and CD8 (double negative alpha/beta T cells). Given the established bone marrow involvement, he was diagnosed with stage IV disease and treated with chemotherapy. His clinical course involved multiple hospitalizations complicated by hyponatremia, neutropenic fevers and pulmonary emboli. Following his fourth cycle of chemotherapy, he developed worsening liver failure and expired approximately three months after initial diagnosis of lymphoma. Hepatosplenic lymphoma of alpha/beta T cells is a rare malignancy with largely unclear risk factors and varied clinical presentations. Notably, diffuse infiltration of liver parenchyma is a prominent feature and the disease can mimic cirrhosis clinically as well as radiographically. Early recognition of this aggressive lymphoma is important and should be considered in the evaluation of patients in whom the etiology of cirrhosis remains in question.

Lymphoma-like T cell infiltration in liver is associated with increased copy number of dominant negative form of TGFβ receptor II

Hepatosplenic T cell lymphoma (HSTCL) is a distinct and lethal subtype of peripheral T cell lymphoma with an aggressive course and poor outcome despite multiagent chemotherapy. Contradictory literature, an unknown etiology, and poor response to treatment highlight the need to define the malignant process and identify molecular targets with potential for successful therapeutic interventions. Herein, we report that mice homozygously expressing a dominant negative TGFβRII (dnTGFβRII) under the control of the CD4 promoter spontaneously develop lymphoma-like T cell infiltration involving both spleen and liver. Splenomegaly, hepatomegaly and liver dysfunction were observed in homozygous dnTGFβRII mice between 10 weeks and 10 months of age associated with a predominant infiltration of CD4⁻CD8⁻TCRβ⁺NK1.1⁺ or CD8⁺TCRβ⁺NK1.1⁻ T cell subsets. Notch 1 and c-Myc expression at the mRNA levels were significantly increased and positively correlated with the cell number of lymphoid infiltrates in the liver of dnTGFβRII homozygous compared to hemizygous mice. Further, 2×10⁴ isolated lymphoma-like cells transplant disease by adoptive cell transfers. Collectively, our data demonstrate that increased copy number of dnTGFβRII is critical for development of lymphoma-like T cell infiltration.