Background: Hepatosplenic T-cell lymphoma (HSTL) is a rare and aggressive form of peripheral T-cell lymphoma that affects the liver and spleen without involving the lymph nodes. It typically occurs in young adults with cytotoxic T-cell proliferation of the TCR γδ type and is associated with immunosuppression. In this case, we present an elderly patient who developed HSTL of the TCR αβ type after being treated for indolent b-cell lymphoma.

Case Presentation: A 76-year-old man with a history of chronic lymphocytic leukemia (CLL) presented with altered mental status. He completed treatment for CLL with obinutuzumab and venetoclax 3 years prior and was in remission. On examination, patient appeared confused. Laboratory data showed hepatocellular liver injury (ALT 342 U/L, AST 800 U/L, ALP 821 U/L, T. Bilirubin 7.1 mg/dL). A CT scan of abdomen and pelvis demonstrated hepatomegaly and mild splenomegaly without lymphadenopathy. Histological analysis of liver biopsy revealed benign hepatocytes with prominent atypical lymphoid infiltrate involving hepatic sinusoids and portal tracts. The lymphoid population appeared atypical with enlarged irregular nucleus and increased apoptosis. Immunohistochemistry revealed atypical lymphoid cells which were positive for CD3, CD2, TCR-β, TIA-1and Granzyme B. The Ki-67 index was up to 40%. Flow cytometry analysis of the peripheral blood demonstrated lack of B-cells and no immunophenotypic abnormal T-cells. The abnormal T-cells were also identified in the bone marrow. The diagnosis of hepatosplenic T-cell lymphoma, TCR- αβ type was rendered. The patient received cyclophosphamide, doxorubicin, etoposide, vincristine, and prednisone with 50% dose reduction due to renal failure. Initially his condition improved; however, on day 5, he developed acute hypoxic respiratory failure secondary to Influenza A and Rhinovirus pneumonia and died from shock and multiorgan failure.

Discussion: HSTL is a rare, aggressive disease with a variable clinical presentation. About 20% of cases occurs in chronic immunosuppression. Our patient had a history of CLL in remission and at HSTL diagnosis, showed hypogammaglobulinemia and no B-cells in the peripheral blood flow cytometry. This clinical setting has not been reported before. Historically, HSTL primarily affects adolescents and young adults, with a median age at diagnosis of approximately 35 years. Most HSTL cases express TCR γδ (~75%) or TCR αβ (~20%), the latter with worse prognosis. There is currently no standard of care treatment, and outcomes are poor without a stem cell transplant.