Heart Tumors: Primary and Metastatic Cardiac Tumors — Overview, Diagnosis & Treatment Options | MyMedicPlus

Primary cardiac tumors are extremely rare (incidence 0.001-0.3% in autopsy series), with benign tumors comprising approximately 75% of cases. Myxoma is the most common primary cardiac tumor (50%), occurring most frequently in the left atrium. Angiosarcoma is the most common malignant primary cardiac tumor. Secondary cardiac tumors from metastases are 20-40 times more common than primary cardiac tumors, with melanoma, lung cancer, breast cancer, and lymphoma being the most frequent primary sources.

Most primary cardiac tumors are sporadic without identifiable cause. Cardiac myxoma is associated with Carney complex (PRKAR1A germline mutation), in which multiple, recurrent myxomas occur in a younger population. Cardiac rhabdomyomas in children are strongly associated with tuberous sclerosis complex (TSC1/TSC2 mutations) and may regress without treatment. Cardiac angiosarcomas have no established risk factors. Metastatic cardiac tumors reflect the natural history of the primary malignancy. Prior thoracic radiation may predispose to secondary cardiac sarcomas.

Symptoms of cardiac tumors result from intracardiac obstruction (dyspnea, syncope, heart failure), embolism (stroke, peripheral arterial occlusion, pulmonary embolism), and constitutional effects (fever, weight loss, elevated inflammatory markers from myxoma-secreted IL-6). Arrhythmias and pericardial effusion cause palpitations and dyspnea. Malignant cardiac tumors may cause rapidly progressive right or left heart failure. Metastatic pericardial disease causes pericardial effusion, tamponade, and constrictive pericarditis.

Transthoracic and transesophageal echocardiography are the first-line diagnostic tools, characterizing tumor location, size, mobility, and attachment. Cardiac MRI with gadolinium provides superior tissue characterization, distinguishing myxoma (heterogeneous T2 signal) from thrombus, lipoma, and malignant tumors (early gadolinium enhancement). CT is used for calcification and extracardiac disease extent. Ga-68 DOTATATE or PSMA PET-CT for metastatic tumors. Biopsy via cardiac surgery or CT-guided provides histological diagnosis when other methods are insufficient.

Cardiac myxoma: prompt surgical resection via cardiotomy with cardiopulmonary bypass is curative; resection should include the stalk attachment with a margin of atrial septum to reduce recurrence. Cardiac rhabdomyoma: observation (most regress in tuberous sclerosis); mTOR inhibitors (everolimus) induce regression. Primary cardiac angiosarcoma: surgical resection if feasible plus doxorubicin-based chemotherapy and radiation; prognosis remains poor. Metastatic pericardial disease: pericardiocentesis for tamponade, pericardial fenestration, or pericardiodesis; systemic treatment of the primary malignancy. Orthotopic cardiac transplantation is considered for selected unresectable primary cardiac sarcomas.

Sporadic cardiac myxoma: recurrence rate of approximately 2-3% after complete resection; patients should undergo annual echocardiography. Carney complex myxoma: recurrence in 20-25% of cases, requiring lifelong surveillance. Primary cardiac angiosarcoma: median survival approximately 6-11 months with multimodality treatment; 5-year survival less than 10%. Metastatic cardiac tumors: prognosis determined by the primary malignancy; cardiac involvement generally indicates widespread disease with poor overall prognosis.

Patients with Carney complex (PRKAR1A mutation) should undergo annual transthoracic echocardiography to detect new myxomas early, starting in childhood. First-degree relatives of Carney complex patients should receive genetic testing. Children with tuberous sclerosis should have echocardiography at diagnosis and periodically thereafter to monitor cardiac rhabdomyoma. No prevention strategies exist for sporadic cardiac tumors. In patients with known metastatic cancers (particularly melanoma and lung cancer), cardiac involvement should be considered in the differential diagnosis of new arrhythmias, unexplained heart failure, or pericardial effusion.