Abstract
A 53-year-old woman with severe erythrocytosis (hemoglobin concentration 19.5 g/dl and hematocrit 0.59) was admitted to our hospital because of fatigue and headache. The serum erythropoietin (Epo) concentration was 68.6 U/l (reference range; 3.7–31.5). Further investigations excluded polycythemia vera or any lung or heart disease. Radiological examination showed a tumor in the left hepatic lobe. Needle biopsies were performed and the histopathological diagnosis was hepatocellular adenoma. Immunohistochemistry demonstrated erythropoietin expression in the adenomatous cells. Liver adenoma is a rare cause of erythrocytosis. For the first time, we report erythropoietin-positive immunoreactivity in liver adenomatous cells in a patient with erythrocytosis.