Pathology of the heart and conduction system in lymphoma and leukaemia.

The clinical and pathological findings in two patients with non-Hodgkin's lymphoma and two patients with T helper cell prolymphocytic leukaemia affecting the heart are described. All four patients had extensive malignant disease, with infiltration of multiple organs. Cardiac infiltration varied from microscopic foci in one case, to grossly identifiable tumour deposits destroying and replacing normal heart structures in three cases. Two patients with infiltration of the conduction system had abnormal electrocardiograms and cardiac dysfunction: one died suddenly, and the other died in heart failure. A third patient with widespread cardiac lymphoma did not show any electrocardiographic abnormalities or dysfunction. Clinicians should be aware of the possibility of cardiac and conduction system disease, particularly in the light of the evolution of specific antitumour chemotherapeutic agents.