Lymphoproliferative disorders of large granular lymphocytes (LGL) can arise from either CD3+ T cells or CD3- natural killer cells. Polyclonal proliferation of LG lymphocytes is called LGL lym- phocytosis, monoclonal proliferation of LG lymphocytes is LGL leukaemia. Prominent clinical manifestations of LGL lymphocytosis and leukaemia are bacterial infections, splenomegaly, and may be connected with rheumatic or autoimmune disorders. Hematologic findings reveal particu- larly lymphocytosis, and severe neutropenia. The b chain gene of T cell receptor rearrangement analysis is necessary for distinguishing of T LGL lymphocytosis from T LGL leukaemia. The authors report a case of young woman with T cells LGL lymphroproliferative disorder, bacte- rial infection, reactive lymphadenopathy, and spontaneous regression of the lymphocytosis wit- hin 6 months.

        Key words: large granular lymphocytes - lymphoproliferatirve disorders - T lymphocytes - natural