Löffler's endocarditis. Occurrence with malignant lymphoma with a high content of epithelioid histiocytes ('Lennert's lymphoma').

In a patient who had malignant lymphoma with a high content of epithelioid histiocytes (so-called Lennert's lymphoma), Löffler's endocarditis developed 18 months after her diagnosis of lymphoreticular malignant neoplasm. She died of refractory congestive heart failure, and an autopsy showed the typical gross and microscopic findings of Löffler's endocarditis. To our knowledge, this is the first reported association of these two diseases. We noted nine autopsy cases in the literature of Löffler's endocarditis occurring in patients with lymphoreticular malignant neoplasms (acute lymphoblastic leukemia and lymphoma). Löffler's endocarditis with eosinophilia may be a relatively uncommon but significant complication in patients with malignant lymphoproliferative disorders. The peripheral blood eosinophilia probably represents a reactive response to tumor antigen.