[Paraneoplastic eosinophilic leukemoid with eosinophilic parietal thromboendocarditis in malignant melanoma].

A case of an eosinophilic leukemoid reaction associated with metastasizing malignant melanoma and thrombotic eosinophilic parietal endocarditis in a 58-year-old white male is reported. No similar cases were found in the literature. The leukemoid reaction with leukocytosis of up to 102 300 white cells per microliter , 65% of which were eosinophils, was observed during the last two months of life of the patient, who died of multiple metastasis of malignant melanoma. The primary malignant melanoma had been excised four years before death. The parietal endocarditis was localized on the posterior wall of the left ventricle and was found incidentally at autopsy. The association of leukemoid eosinophilic reaction with consecutive eosinophilic thrombotic parietal endocarditis is believed to be part of a paraneoplastic syndrome. 63 published cases of paraneoplastic eosinophilic leukemoid reaction and 6 published cases of malignant tumor with eosinophilia and additional parietal endocarditis were found. The pathogenesis of these conditions is discussed.