[Coincidence of chronic idiopathic myelofibrosis and chronic lymphocytic leukaemia. A rare phenomenon?].

In 1986 we diagnosed chronic idiopathic myelofibrosis (CIMF) in a 45-year-old asymptomatic patient with hepatosplenomegaly. In 1996 splenectomy was performed because of hypersplenism, and chemotherapy with hydroxyurea was initiated. In 1999 generalised lymphadenopathy of chronic lymphocytic leukaemia (B-CLL) developed. A trephine biopsy showed leukaemic bone marrow infiltration. On heteroduplex analysis we found a clonal rearrangement of IgH in the leukaemic lymphocytes. The coincidence of chronic myeloproliferative and lymphoproliferative diseases in the same patient is a rare phenomenon. According to the relevant literature, seven cases with a combination of CIMF/CLL have been reported. Possible pathomechanisms for the development of such coincidences are: 1) a bilineage manifestation of a pluripotent stem cell proliferation, 2) independent proliferations of two distinct cell lines under a common leukaemogenic stimulus or 3) an accidental association. These coincidence cases often showed a mild clinical course and also in our case, the patient is still alive and in a stable disease condition 16 years after the initial diagnosis.