PO-212 Morphological heterogeneity of hepatosplenic gamma/delta T-cell lymphoma

Abstract

IntroductionHepatosplenic gamma/delta T-cell Lymphoma (HSTL) is a systemic extra-nodal lymphoma originating from cytotoxic T-cells expressing the gd receptor. We report clinical, morphologic and phenotypic characteristics of 3 patients with HSTL.Material and methodsAll patients were male and presented at a mean age of 23 years. One was treated with azathioprine for inflammatory bowel disease, the two others had no history of immunosuppression. All patients were admitted to the hospital with high fever and hepatosplenomegaly. Two presented severe abdominal pain and lymphadenopathy.Laboratory studies of the three patients were different:Case 1: thrombopenia and bone marrow infiltration with 69% of large lymphomatous blast cells and minimal peripheral blood infiltration.Case 2: pancytopenia without excess of blasts in the peripheral blood and moderate bone marrow infiltration in cytometry. Morphological and immune-phenotypical studies of the spleen (after splenectomy) showed a massive infiltration by lymphocytic small cells.Case 3: pancytopenia with 25% and 45% of blast cells in the peripheral blood and bone marrow aspirate respectively.Immuno-phenotyping showed a T lymphocytic population double negative (CD3pos CD4neg CD8neg to dim) with gamma-delta expression, CD1a- CD2 +CD5 CD7+CD56+CD57 in all 3 patients.Two patients underwent an initial treatment with Cyclophosphamide, Doxorubicin, Vincristine and Prednisone: the first died after 4 months, and there is no response to treatment in the second patient. Treatment was recently initiated in the third patient.Results and discussionsIn our series, HSTL confirmed a predilection to develop most often in young men with hepatosplenomegaly. Variable degrees of hematologic abnormalities were observed. Thrombocytopenia was the most striking finding in all. Bone marrow involvement is described in approximately two thirds of patients but was observed by immunophenotyping in our 3 cases. We show that immunophenotyping seems to be the best method for the rapid characterisation of the lymphoma cells morphologically heterogeneous and difficult to identify.ConclusionHSTL is an infrequent, rare aggressive tumour. The diagnosis is difficult. There is no treatment consensus and the prognosis remains poor.