Lymphoprolifération systémique T liée à l'EBV chez l'enfant

Systemic EBV+ T-cell lymphoproliferative disease of childhood is a recent entity described in the 2008 World Health Organisation tumours of haematopoietic system and lymphoid tissues as a clonal T-cell EBV+ systemic proliferation. It occurs after acute or chronic active EBV infection. We report the case of a caucasian, immunocompetent 12-year-old girl, with no particular history, who presented with hemophagocytic lymphohistiocytosis in the aftermath of an infectious mononucleosis. Main symptoms were multiple organ failure, hepatosplenomegaly and pancytopenia. Histopathology of peripheral lymph node and bone marrow revealed a T-cell, CD8+, EBV+ lymphoproliferation. An elevated viral load was detected in blood by PCR. The patient died within 3 weeks. Since most of the cases have been reported in Asia and South America, few cases still have been described in Europe. Unlike B-cell lymphoproliferation in immunocompromised individuals, T-cell EBV+ lymphoproliferation occurs in immunocompetent patients and seems to be the consequence of a proliferative disorder of EBV-infected T-cells, attributed to a cytotoxic T-cell response deficiency. These T-cell proliferations are more frequently immunoreactive for CD8 than CD4. A key feature of the diagnosis might be EBV viral load.