Practice Essentials
Primary cardiac tumors (PCTs) occur along a pathologic spectrum that includes benign, malignant, and intermediate with uncertain biological behavior. More than 90% of PCTs are benign; most of these are myxomas (see the images below), which account for 40-50% of all PCTs. [1] Other benign PCTs are rhabdomyomas, papillary fibroelastoma, fibromas, hemangiomas, lipomas, and leiomyomas. Only 5% to 6% of PCTs are malignant. The most common malignant tumors are sarcomas, followed by lymphomas and mesotheliomas. Less than 1% are classified as intermediate; these include paragangliomas, inflammatory myofibroblastic tumors, and germ cell tumors (ie, mature teratoma and yolk sac tumors). [2, 3]
High-power photomicrograph showing the histology of cardiac myxoma (hematoxylin and eosin stain). Note the dark staining polygonal cells characteristic of the tumor.
No distinct cause of cardiac tumors is known. Although the overall incidence of primary cardiac neoplasms is low (0.0001-0.5% in autopsy series), these tumors provide unique diagnostic and therapeutic challenges. [4, 5, 6, 7] The differential for cardiac masses includes PCTs, malignant cardiac metastases, as well as thrombus, Lambl excrescences, and pericardial cysts. [3]
The signs and symptoms caused by cardiac tumors are generally secondary to their mass effect, local invasion, or embolization, or are constitutional. An intracardiac tumor mass may obstruct blood flow, compromise valve function, or induce neurologic catastrophe secondary to tumor embolization. The location of the tumor determines the type of clinical manifestations produced, which can include syncope, angina, dyspnea, edema, ascites, depression of pump function, cardiomyopathy, and pulmonary hypertension. Some tumors produce no symptoms and are found incidentally as a consequence of secondary complications such as stroke or evidence of peripheral embolization.
Most benign tumors can be resected completely with excellent outcomes. Heart transplantation may be appropriate in those instances in which the benign tumor is too large to resect. Resection is the treatment of choice for malignant cardiac tumors; however, long-term results are dismal, even with the addition of adjuvant therapy. [8]
Pathophysiology
Several types of tumors can arise in the heart, depending upon the tissues and structures involved. Primary neoplasms may arise from endocardium, valvular structures, primitive tissue rests, and the conduction system. Secondary or metastatic neoplasms arise from hematologic spread of the originating tissue. The physiologic derangements induced by the tumor depend on the location of the mass and the tissue from which it arises.
Epidemiology
Frequency
United States
Incidence depends upon tumor cell type. Overall incidence of the disease is 0.0001-0.5% in autopsy series. Myxomas account for 40-50% of primary cardiac tumors in patients aged 30-60 years.
International
Rates of cardiac tumors in other countries parallel rates in the United States.
Race-, sex-, and age-related demographics
Primary cardiac tumors appear to occur equally in all races, unless their presence is connected directly with underlying genetic disorders that demonstrate a race predilection. The frequencies of these tumors in males and females are the same.
Cardiac tumors can occur in all age groups, but the following variations are seen:
Prognosis
Prognosis for benign tumors is excellent, matching that of the healthy population. [12] Malignant tumors carry a dismal prognosis even in the face of complete resection. An occasional sarcoma can be resected completely, resulting in long-term survival.
An analysis of outcomes of 747 patients with primary cardiac malignant tumors found a 90-day mortality rate of 29.4% following surgical treatment. Overall 30-day, 1-year, and 5-year survival rates were 81.2%, 45.3%, and 11.5%, respectively. For stage III disease, there was a statistically significant improvement in survival with the addition of chemotherapy to surgery. [13]
Myxomas: The mortality rate of patients after myxoma removal does not differ significantly from that of the general population.
Rhabdomyoma, fibroma, fibroelastoma, hemangioma, lipoma, teratoma, and hamartoma: These are benign tumors, and mortality rates in patients with these tumors do not differ significantly from that of the general population.
Malignant tumors: These tumors are generally sarcomatous in nature. In spite of resections (complete or incomplete), median survival duration ranges from 10-24 months.
Complications encountered after resection of cardiac tumors can include valvular insufficiency, complete heart block requiring pacemaker insertion, atrial and ventricular arrhythmias, and stroke.
-
Low-power photomicrograph of cardiac myxoma (hematoxylin and eosin stain).
-
High-power photomicrograph showing the histology of cardiac myxoma (hematoxylin and eosin stain). Note the dark staining polygonal cells characteristic of the tumor.
