Simultaneous or spontaneous occurrence of lympho- and myeloproliferative disorders: a report of four cases.

We describe four patients with mixed lympho- and myeloproliferative disorders. One patient had hairy cell leukaemia and acute myelomonocytic leukaemia, another lymphocytic lymphoma in leukaemic phase and chronic myelomonocytic leukaemia and the third patient had chronic lymphocytic leukaemia and polycythaemia rubra vera; none of these patients had received any prior therapy, and in two the diagnosis of the two malignancies was simultaneous. The fourth patient developed acute monocytic leukaemia 4 years after the diagnosis of chronic lymphocytic leukaemia after only 2 weeks of therapy with chlorambucil. The nuber of cases with concurrent or sequential but spontaneous occurrence of lympho- and myeloproliferative disorders reported so far is now 38. The questions relating to the pathogenesis of the two malignancies are discussed.