Simultaneous diagnosis of CD3+ T-cell large granular lymphocyte leukaemia and true thymic hyperplasia.

CD3+ T-cell large granular lymphocyte (LGL) leukaemia is a mature T-cell neoplasm of cytotoxic T-lymphocytes. Neutropenia represents the most frequent peripheral blood cytopenia associated with CD3+ T-cell LGL leukaemia. A wide variety of diseases associated with LGL leukaemia have been reported, both autoimmune and neoplastic. We describe for the first time the association of true thymic hyperplasia with CD3+ T-cell line LGL leukaemia. The patient presented with severe symptomatic neutropenia. Complete and persistent haematological and molecular remission was induced with an association of low-dose methotrexate and cyclosporin A, followed by thymectomy.