RT Journal A1 SIGGILLINO JJ, CRAWLEY CJ, CLAUSS RH, REED GE, TICE DA T1 MYxoma of the right atrium with polycythemia JF Archives of Internal Medicine JO Archives of Internal Medicine YR 1963 FD February 1 VO 111 IS 2 SP 178 OP 183 DO 10.1001/archinte.1963.03620260038007 UL http://dx.doi.org/10.1001/archinte.1963.03620260038007 AB Primary neoplasms of the heart are rare and have been observed by Straus and Merliss in only 0.0017% of 480,000 autopsies. Myxoma is the most frequent primary tumor of the heart and accounts for approximately 50% of the reported cases.1,2 In 1953 Steinberg reviewed 204 cases of cardiac myxoma, 25% occurring in the right atrium. Myxoma of the left atrium is 3 times more frequent than that of the right atrium. A less frequent site is the left ventricle. Many of the cases reported presented with symptoms of mitral or tricuspid stenosis.Myxoma is a benign tumor, often pedunculated, which usually arises from the atrial septum in the region of the fossa ovalis. The majority occur in persons in the sixth decade of life.The prevailing opinion concerning cardiac myxoma is that it represents either a true neoplastic growth or is the result of an organized blood clot of