- Author: Gyanendra K Sharma, MD, FACC, FASE; Chief Editor: Park W Willis IV, MD more...
Atrial myxomas are the most common primary heart tumors. Because of nonspecific symptoms, early diagnosis may be a challenge. Left atrial myxoma may or may not produce characteristic findings on auscultation. Two-dimensional echocardiography is the diagnostic procedure of choice. Most atrial myxomas are benign and can be removed by surgical resection.
Myxomas account for 40-50% of primary cardiac tumors. Approximately 90% are solitary and pedunculated, and 75-85% occur in the left atrial cavity. Up to 25% of cases are found in the right atrium. Most cases are sporadic. Approximately 10% are familial and are transmitted in an autosomal dominant mode. Multiple tumors occur in approximately 50% of familial cases and are more frequently located in the ventricle (13% vs 2% in sporadic cases).
Myxomas are polypoid, round, or oval. They are gelatinous with a smooth or lobulated surface and usually are white, yellowish, or brown. The most common site of attachment is at the border of the fossa ovalis in the left atrium, although myxomas can also originate from the posterior atrial wall, the anterior atrial wall, or the atrial appendage. The mobility of the tumor depends upon the extent of attachment to the interatrial septum and the length of the stalk.
Although atrial myxomas are typically benign, local recurrence due to inadequate resection or malignant change has been reported. Occasionally, atrial myxomas recur at a distant site because of intravascular tumor embolization. The risk of recurrence is higher in the familial myxoma syndrome.
Symptoms from a cardiac myxoma are more pronounced when the myxomas are left-sided, racemosus, and over 5 cm in diameter. Symptoms are produced by mechanical interference with cardiac function or embolization. Being intravascular and friable, myxomas account for most cases of tumor embolism. Embolism occurs in about 30-40% of patients. The site of embolism is dependent upon the location (left or right atrium) and the presence of an intracardiac shunt.
Jong-Won Ha and associates reported a more frequent occurrence of systemic embolism in polypoid tumors as compared to round (58% vs 0%). Also, polypoid tumors more frequently prolapse into the ventricle. Prolapse of a tumor through the mitral or tricuspid valve may result in the destruction of the annulus or valve leaflets. In one study, 19% of the patients had atrial fibrillation associated with large atrial myxoma. Left atrial myxomas produce symptoms when they reach about 70 g. Right atrial myxomas grow to approximately twice this size before becoming symptomatic. Tumors vary widely in size, ranging from 1-15 cm in diameter. Rate of growth is not exactly known. In one case report, right atrial myxoma had a growth rate of 1.36 X 0.03 cm/mo. The myxomas are vascular tumors and may be neovascularized by a branch of a coronary artery. Recently, a case of hemorrhage in a left atrial myxoma was reported.
Myxomas have been demonstrated to produce numerous growth factors and cytokines, including vascular endothelial growth factor, resulting in angiogenesis and tumor growth and an increased expression of the inflammatory cytokine, interleukin-6.[6, 7, 8]
Most cases of atrial myxoma are sporadic, and the exact etiology is unknown.
Familial atrial myxomas have an autosomal dominant transmission.
Carney syndrome is genetically heterogenous and is caused by a defect in more than one gene. It is estimated to account for 7% of all atrial myxomas without any predilection for age or sex. Abnormalities in the short arm of chromosome 2 (Carney) and chromosome 12 (Ki-ras oncogene) have been described. In a recent case report, a frame-shift mutation was found in exon 2 in the causative gene of Carney complex, protein kinase A regulatory subunit 1 alpha (PRKAR1A).
United States statistics
Based upon the data of 22 large autopsy series, the prevalence of primary cardiac tumors is approximately 0.02% (200 tumors per million autopsies). About 75% of primary tumors are benign, and 50% of benign tumors are myxomas, resulting in 75 cases of myxoma per million autopsies.
Surgical incidence in the Republic of Ireland from 1977-1991 was 0.50 atrial myxomas per million population per year.
Sex- and age-related demographics
Approximately 75% of sporadic myxomas occur in females. In a series of 66 cardiac myxomas, the female-to-male ratio was 2.7:1. However, female sex predominance is less pronounced in familial atrial myxomas. In a retrospective analysis of 367 patients, there were 28 cases of right atrial myxoma, of which 16 were males and 12 were females.
Myxomas have been reported in patients aged 3-83 years. The mean age for sporadic cases is 56 years; whereas it is 25 years for familial cases. In a retrospective review of 171 patients from India, the mean age of presentation was 37.1 years. Most of these patients were symptomatic; dyspnea was the most common symptom.
Sudden death may occur in 15% patients with atrial myxoma. Death is typically caused by coronary or systemic embolization or by obstruction of blood flow at the mitral or tricuspid valve.
Morbidity is related to symptoms produced by tumor embolism, heart failure, mechanical valvular obstruction, and various constitutional symptoms.
In a single-center study of 62 patients with cardiac myxoma, actuarial survival was 96.8 ± 1.8% at 10 years. Most patients were asymptomatic following the surgery, without recurrence. Recurrence occurred only in 2 familial cases of left atrial myxoma. Freedom from reoperation was 98.4 ± 1.3% at 5 years and 96.8 ± 1.8% at 10 years.
Complications of atrial myxoma include the following:
Congestive heart failure
Larsson S, Lepore V, Kennergren C. Atrial myxomas: results of 25 years' experience and review of the literature. Surgery. 1989 Jun. 105(6):695-8. [Medline].
Obrenovic-Kircanski B, Mikic A, Parapid B, et al. A 30-year-single-center experience in atrial myxomas: from presentation to treatment and prognosis. Thorac Cardiovasc Surg. 2013 Sep. 61(6):530-6. [Medline].
Ha JW, Kang WC, Chung N. Echocardiographic and morphologic characteristics of left atrial myxoma and their relation to systemic embolism. Am J Cardiol. 1999. 83:1579-1582. [Medline].
Hasdemir H, Alper AT, Arslan Y, Erdinler I. [Left atrial myxoma with severe neovascularization: role of preoperative coronary angiography]. Turk Kardiyol Dern Ars. 2011 Mar. 39(2):163-5. [Medline].
Park J, Song JM, Shin E, Jung SH, Kim DH, Kang DH, et al. Cystic cardiac mass in the left atrium: hemorrhage in myxoma. Circulation. 2011 Mar 15. 123(10):e368-9. [Medline].
Sakamoto H, Sakamaki T, Kanda T, Tsuchiya Y, Sato M, Sato H. Vascular endothelial growth factor is an autocrine growth factor for cardiac myxoma cells. Circ J. 2004 May. 68(5):488-93. [Medline].
Mendoza CE, Rosado MF, Bernal L. The role of interleukin-6 in cases of cardiac myxoma. Clinical features, immunologic abnormalities, and a possible role in recurrence. Tex Heart Inst J. 2001. 28(1):3-7. [Medline].
Kono T, Koide N, Hama Y, et al. Expression of vascular endothelial growth factor and angiogenesis in cardiac myxoma: a study of fifteen patients. J Thorac Cardiovasc Surg. 2000 Jan. 119(1):101-7. [Medline].
Imai Y, Taketani T, Maemura K, Takeda N, Harada T, Nojiri T. Genetic analysis in a patient with recurrent cardiac myxoma and endocrinopathy. Circ J. 2005 Aug. 69(8):994-5. [Medline].
Zheng JJ, Geng XG, Wang HC, Yan Y, Wang HY. Clinical and histopathological analysis of 66 cases with cardiac myxoma. Asian Pac J Cancer Prev. 2013. 14(3):1743-6. [Medline].
Li H, Guo H, Xiong H, Xu J, Wang W, Hu S. Clinical features and surgical results of right atrial myxoma. J Card Surg. 2015 Nov 19. [Medline].
Aggarwal SK, Barik R, Sarma TC, Iyer VR, Sai V, Mishra J. Clinical presentation and investigation findings in cardiac myxomas: new insights from the developing world. Am Heart J. 2007 Dec. 154(6):1102-7. [Medline].
Patil NP, Dutta N, Satyarthy S, Geelani MA, Kumar Satsangi D, Banerjee A. Cardiac myxomas: experience over one decade. J Card Surg. 2011 Jul. 26(4):355-9. [Medline].
Pergolini A, Zampi G, Sbaraglia F, Musumeci F. Left atrial myxoma: two sides of the same coin. J Cardiovasc Med (Hagerstown). 2013 Jun 7. [Medline].
Jha GN. Ascites--rare manifestation of right atrial myxoma. J Assoc Physicians India. 2014 Apr. 62(4):349-50. [Medline].
Lee VH, Connolly HM, Brown RD Jr. Central nervous system manifestations of cardiac myxoma. Arch Neurol. 2007 Aug. 64(8):1115-20. [Medline].
Singh PK, Sureka RK, Sharma AK, Bhuyan S, Gupta V. Recurrent stroke in a case of left atrial myxoma masquerading vasculitis. J Assoc Physicians India. 2013 Dec. 61(12):912, 917-20. [Medline].
Smith MJ, Chaudhry MA, Humphrey MB, Lozano PM. Atrial myxoma and bone changes: a paraneoplastic syndrome?. J Card Surg. 2011 Jul. 26(4):375-7. [Medline].
Furukawa A, Kishi S, Aoki J. Large Infected Atrial Myxoma With Vegetations. Rev Esp Cardiol. 2011 Jul 21. [Medline].
Lanjewar DN, Bhatia VO, Lanjewar SD, Carney JA. Cutaneous myxoma: An important clue to Carney complex. Indian J Pathol Microbiol. 2014 Jul-Sep. 57(3):460-2. [Medline].
Ryou KS, Lee SH, Park SH, Park J, Hwang SK, Hamm IS. Multiple fusiform myxomatous cerebral aneurysms in a patient with Carney complex. J Neurosurg. 2008 Aug. 109(2):318-20. [Medline].
Scheffel H, Baumueller S, Stolzmann P, Leschka S, Plass A, Alkadhi H. Atrial myxomas and thrombi: comparison of imaging features on CT. AJR Am J Roentgenol. 2009 Mar. 192(3):639-45. [Medline].
Gheysens O, Cornillie J, Voigt JU, Bogaert J, Westhovens R. Left Atrial Myxoma on FDG-PET/CT. Clin Nucl Med. 2013 Mar 18. [Medline].
Hajj-Chahine J, Jayle C, Houmaida H, Corbi P. Utility of genetic testing in multisite myxoma to rule out Carney complex. Interact Cardiovasc Thorac Surg. 2011 Apr. 12(4):624. [Medline].
Acebo E, Val-Bernal JF, Gomez-Roman JJ, Revuelta JM. Clinicopathologic study and DNA analysis of 37 cardiac myxomas: a 28-year experience. Chest. 2003 May. 123(5):1379-85. [Medline].
Lopez-Marco A, BinEsmael T, Rowlands G, Von Oppell U. Complete calcification of right atrial myxoma. Eur J Cardiothorac Surg. 2014 Oct 25. [Medline].
Kesavuori R, Raivio P, Jokinen JJ, Sahlman A, Vento A. Quality of life after robotically assisted atrial myxoma excision. J Robot Surg. 2015 Sep. 9 (3):235-41. [Medline].
Owers CE, Vaughan P, Braidley PC, Wilkinson GA, Locke TJ, Cooper GJ, et al. Atrial myxomas: a single unit's experience in the modern era. Heart Surg Forum. 2011 Apr 1. 14(2):E105-9. [Medline].
Baikoussis NG, Papakonstantinou NA, Dedeilias P, et al. Cardiac tumors: a retrospective multicenter institutional study. J BUON. 2015 Jul-Aug. 20 (4):1115-23. [Medline].
Pinede L, Duhaut P, Loire R. Clinical presentation of left atrial cardiac myxoma. A series of 112 consecutive cases. Medicine (Baltimore). 2001 May. 80(3):159-72. [Medline].
Sheng WB, Luo BE, Liu Y, Zhang H, Zou LJ, Xu ZY, et al. Risk factors for postoperative recurrence of cardiac myxoma and the clinical managements: a report of 5 cases in one center and review of literature. Chin Med J (Engl). 2012 Aug. 125(16):2914-8. [Medline].
Shah IK, Dearani JA, Daly RC, et al. Cardiac myxomas: a 50-year experience with resection and analysis of risk factors for recurrence. Ann Thorac Surg. 2015 Aug. 100 (2):495-500. [Medline].
Deshpande RP, Casselman F, Bakir I, Cammu G, Wellens F, De Geest R. Endoscopic cardiac tumor resection. Ann Thorac Surg. 2007 Jun. 83(6):2142-6. [Medline].
Vroomen M, Houthuizen P, Khamooshian A, Soliman Hamad MA, van Straten AH. Long-term follow-up of 82 patients after surgical excision of atrial myxomas. Interact Cardiovasc Thorac Surg. 2015 Aug. 21 (2):183-8. [Medline].
Basson CT, MacRae CA, Korf B. Genetic heterogeneity of familial atrial myxoma syndromes (Carney complex). Am J Cardiol. 1997 Apr 1. 79(7):994-5. [Medline].