A Case of Metanephric Adenoma and Acute Myocardial Infarction.

Metanephric adenoma (MA) is a rare neoplasm that acounts for 0.2% of adult renal neoplasms. MAs are typically discover incidentally during detailed examinations for nonspecific symptoms such as abdominal or flank pain, hematuria, fever and palpable abdominal mass. Additionally, polycythemia has occasionally been reported as well. Herein we describe a case of metanephric adenoma which was an incidental finding in the course of a clinical autopsy in a patient with complete AV block and polycythemia. Histologically, the tumor was composed of small and uniform tubular structures reminiscent of renal tubuli, without signs of cellular atypia and pleomorphism. Such tumor histomorphology was consistent with the diagnosis of metanephric adenoma. Thrombosis is a common complication of polycythemia that often causes death. Polycythemia with an increasing number of blood cells causes hyperviscosity and, in 20-40% of cases, lethal thrombosis or hemorrhage. Hyperviscosity and coronary artery disease in our patient caused acute myocardial infarction with the subsequent rupture of posterior left ventricle wall and hemopericardium.