Hepatosplenic γδ T-cell Lymphoma is a Rare Clinicopathologic Entity with Poor Outcome: Report on a Series of 21 Cases. Short title: HEPATOSPLENIC γδ T-CELL LYMPHOMA

We report on the characteristics of 21 cases of Hepatosplenic γδ T-cell lymphoma (HSγδTCL), an entity recognized since 1994 by the REAL classification. Median age was 34 years. Patients presented with splenomegaly (n=21), hepatomegaly (n=15) and thrombocytopenia (n=20). Histopathologic findings were homogeneous with the presence of medium-sized lymphoma cells within the sinusoids of splenic red pulp, liver and bone marrow. Marrow involvement was usually mild but could be demonstrated by phenotyping in all cases. Cells were CD3+, CD5-, expressed the γδ T-cell receptor and had a non-activated cytotoxic cell phenotype (TIA-1+, granzyme B-). Most cases were CD4-/CD8(16/18), CD56+ (15/18), expressed the Vδ1epitope (Vd1+/Vd2-/Vd3-, 9/12) and were negative for EBV (18/20). An isochromosome 7q was found in nine of 13 documented cases. Eight patients had a previous history of kidney transplant, systemic lupus, Hodgkin disease or malaria. Prognosis was very poor with a median survival time of 16 months and all patients but two ultimately dying despite consolidative or salvage high-dose therapy. In conclusion, HSγδTCL is a disease with distinctive clinical, histopathologic and phenotypic characteristics. Bone marrow biopsy with combined phenotyping is sufficient for diagnosis and splenectomy is therefore unwarranted. Current treatment modalities appear to be ineffective in most cases. For personal use only. on November 12, 2017. by guest www.bloodjournal.org From