Abstract

1. Abstract
1.1. Background: Erythrocytosis may result from primary or secondary causes. Primary erythrocytosis results from abnormalities that lead to constant overproduction of red cells and low erythropoietin (EPO) levels. EPO-producing tumors such as hepatocellular carcinoma and renal cell carcinoma are well known secondary causes. Paragangliomas are rare tumors characterized by increased release of catecholamines with symptoms more commonly hematuria, hypertension, headache and post-micturition syncope.