Cardiac tumors, though rare, present a diagnostic and clinical challenge in medical practice. Among primary tumors, which have an estimated prevalence of 0.02%, benign types such as myxomas predominate. However, malignant tumors, such as sarcomas, still have a poor prognosis. The majority of secondary tumors are metastatic, originating from pulmonary or breast carcinomas, and are often detected incidentally. This work addresses the differences between the various types of tumors to adapt treatment accordingly and emphasizes the importance of early detection.

This is a review of the most relevant literature to date, analyzing retrospective and prospective studies, as well as international guidelines. It describes the classification and prevalence of cardiac tumors, as well as therapeutic options, which are discussed based on histology and aggressiveness. Clinical manifestations, imaging diagnostics, surgical approaches, and adjuvant chemotherapy and radiotherapy treatments are explained.

Depending on the tumor’s characteristics, they are classified as follows:

Primary Benign Tumors

• Myxoma: The most common type of primary cardiac tumor. It primarily affects women aged 30–60 years. Its typical location is the interatrial septum of the left atrium. Myxomas are polypoid and round in shape. First-line treatment is surgery.
• Rhabdomyoma: The most frequent cardiac tumor in children, involving the myocardium of both ventricles and the interventricular septum. It may regress spontaneously. Surgical treatment is required in certain cases.
• Papillary Fibroelastoma: This tumor appears as a small, rounded, pedunculated valvular mass with multiple projections, predominantly affecting the aortic valve. Some authors suggest it may be the most frequent primary cardiac tumor, surpassing myxomas, as noted in prior blog entries. It poses an embolic risk, and surgical treatment is indicated either after embolic events or prophylactically.
• Fibroma: Common in infants and children, it appears as a solitary mass affecting the free wall of the left ventricle and the ventricular septum. It is associated with Gorlin-Goltz syndrome. Surgical treatment is recommended.
• Lipoma: Originating from mature adipocytes encapsulated by collagen, lipomas often affect the endocardium of the right atrium, the left ventricle, and the pericardium. Treatment is surgical.
• Hemangioma: Characterized by endothelial cell proliferation leading to increased vascularization. Its most frequent location is the right atrium. Surgery is generally the treatment of choice.

Primary Malignant Tumors

• Angiosarcoma: The most common type of malignant cardiac tumor with the poorest prognosis. It is primarily diagnosed in middle-aged men and shows a predilection for the right atrium. Surgery is the preferred treatment.
• Rhabdomyosarcoma: The second most common malignant cardiac tumor, originating from undifferentiated skeletal tissue. It frequently infiltrates the pericardium and cardiac valves. Treatment requires a multimodal approach.
• Leiomyosarcoma: A soft tissue sarcoma with smooth muscle characteristics. It is most commonly found in the left atrium and may resemble a myxoma in imaging studies. Surgery is the primary treatment.
• Undifferentiated Pleomorphic Sarcoma: A high-grade sarcoma with variable morphology, including nuclear pleomorphism and spindle-shaped cells.
• Osteosarcoma: Extremely rare and predominantly observed in the left atrium. Subtypes include osteoblastic, chondroblastic, and fibroblastic variants.
• Synovial Sarcoma: More frequent in men, this tumor affects the pericardium and the right ventricular outflow tract. It is large and encased in fibrous pseudocapsules.
• Fibrosarcoma: A mesenchymal-origin tumor. Treatment includes surgery and, in some cases, transplantation. In pediatric fibrosarcomas, TRK inhibitors may be used.
• Lymphoma: Usually a non-Hodgkin type, most commonly affecting the right atrium. Treatment involves chemotherapy with CHOP or CHOP plus Rituximab regimens.

Secondary or Metastatic Tumors

• Primary cancer sites that frequently metastasize to the heart include lung, skin melanoma, breast, esophagus, and hematological malignancies. The most common location is the pericardium, accounting for two-thirds of cases.
• In selected cases, surgical resection may be performed, including the use of cardiopulmonary bypass.

Clinical Manifestations and Diagnosis

The symptoms of cardiac tumors depend on their location, size, and histological type. Benign tumors, such as myxomas, can cause valvular obstruction, arrhythmias, or embolic phenomena. Malignant tumors often present with more severe symptoms due to rapid progression and invasive potential. Symptoms can be classified as:

• Obstructive symptoms: Dyspnea, pulmonary edema, or syncope.
• Embolic symptoms: Stroke or peripheral embolism.
• Systemic symptoms: Fever, weight loss, or fatigue.

It is important to note that a large percentage of cardiac tumors are asymptomatic and are incidentally detected during imaging studies performed for other reasons.

Advancements in imaging techniques have significantly improved the diagnosis of cardiac tumors. Transthoracic echocardiography is the initial tool in most cases, offering detailed visualization of small, mobile masses and assessing intracardiac flow. Magnetic resonance imaging (MRI) and computed tomography (CT) complement echocardiography by providing information on tumor extent, composition, and potential local invasion.

Positron emission tomography (PET) is used to evaluate tumor metabolic activity and differentiate between benign and malignant lesions.

Management and Prognosis of Cardiac Tumors

The management of cardiac tumors depends on their histological type, size, and location.

• Benign Tumors: Surgical resection is typically curative.
• Malignant Tumors: These require a multimodal approach, including:
  • Surgery: Aimed at reducing tumor mass. Achieving complete resection without residual disease (R0) is rare; microscopic residual disease (R1) is desired, though gross residual disease (R2) is unfortunately more common.
  • Adjuvant Therapy: Chemotherapy and radiotherapy are used to control tumor growth and prevent or manage recurrence.

Surgical treatment for malignant tumors has been analyzed in previous blog entries.

The prognosis of malignant tumors is generally poor due to their aggressive nature and late diagnosis. Secondary tumors reflect advanced systemic disease and also have a poor prognosis.

COMMENTARY:

This article provides a comprehensive overview of cardiac tumors from a practical perspective. On one hand, identifying benign tumors like myxomas or fibroelastomas can lead to curative surgeries, significantly improving patients’ quality of life and preventing tumor-related complications, such as embolism. On the other hand, it highlights the challenges associated with malignant tumors, especially sarcomas, where late diagnosis and disease aggressiveness limit therapeutic options.

One of the key contributions of this work is emphasizing the importance of a multidisciplinary approach in complex cases. Furthermore, it raises critical questions for the future: How can we improve early detection? Is it possible to develop more effective treatments for malignant tumors? The need for specific guidelines for their management is also underlined as a critical area for future development.

In daily clinical practice, we must maintain a high index of suspicion in patients with nonspecific symptoms, as these could conceal a cardiac tumor. Moreover, these tumors should be included in the differential diagnosis of any intracardiac mass.

This article not only provides detailed information on the various types of cardiac tumors, their diagnosis, and management but also underscores the importance of an integrated, individualized approach to improve outcomes in this field.

REFERENCE:

Karigyo CJT, Pessoa BMS, Nicacio SP, Terwilliger E, Costa P, Santos PRD, et al. Cardiac Tumors: Review. Braz J Cardiovasc Surg. 2024 Jul 22;39(6):e20230405. doi: 10.21470/1678-9741-2023-0405.