Tumors of the heart can either be benign (non-cancerous) or malignant (cancerous). There are certain tumors that are classified as atypical (uncertain or unspecified behavior) meaning that some behave in a benign manner, or some behave in a malignant manner. A majority of the cardiac tumors diagnosed via lab studies (biopsy) are benign.

The World Health Organization (WHO) is an authoritative body that compiles, prepares, and publishes histological and molecular classification of tumors, via their Blue Books, based on research inputs from experts worldwide. These reference books chiefly aid in global cancer research, provide gold standards for tumor diagnosis, and help in treating cancer patients.

According to the WHO Classification of Thoracic Tumors (2021), 5th Ed., Vol.5, benign and malignant tumors of the heart are classified in the following manner:

Tumors of the heart:

Benign tumors

• Papillary fibroelastoma: It is a common benign tumor of the heart valves that develops in both children and adults
• Cardiac myxoma: It is one of the most common benign tumors of the heart that is observed in a wide age range of individuals
• Cardiac fibroma: It is a very rare, connective tissue tumor of the heart, which is mostly observed in infants and children. This benign tumor is mostly present in the ventricles of the heart
• Cardiac rhabdomyoma: It is a benign tumor of the heart muscle that is generally diagnosed in infants and very young children
• Adult cellular rhabdomyoma: It is a benign tumor that usually forms in the upper chambers of the heart. It is a very rare condition that is typically seen in middle-aged adults
• Cardiac lipoma and lipomatous hypertrophy of the atrial septum: Cardiac Lipoma is a rare benign tumor that is mostly seen to involve the pericardium and epicardium. Lipomas are very common tumors of fat tissues that observed in both children and adults
• Lipomatous hamartoma of the atrioventricular valve
• Hamartoma of mature cardiac myocytes: It is an abnormal growth of the heart muscles and is generally observed in adults. It is a rare benign condition of the heart
• Mesenchymal cardiac hamartoma
• Cardiac hemangiomas: These are rare tumors that are observed in both children and adults. Hemangiomas are benign malformation of blood vessels that can occur at various body locations
• Conduction system hamartoma
• Cystic tumor of the atrioventricular node: It is a benign congenital tumor that is located in the heart atrium, near the atrioventricular node. The tumor may be diagnosed during childhood or into adulthood

Malignant tumors

• Cardiac angiosarcoma: It is an infrequent and aggressive, but often rapidly developing tumor of the heart that presents no signs and symptoms in the early stages. Children and adults of a wide age category are known to be affected
• Cardiac leiomyosarcoma: It is mostly observed to form in the left atrium in middle-aged and older adults. Leiomyosarcoma is a rare type of connective tissue cancer
• Cardiac undifferentiated pleomorphic sarcoma
• Other sarcomas that may involve the heart

Hematolymphoid tumors

• Hematolymphoid tumors of the heart
• Cardiac diffuse large B-cell lymphoma
• Cardiac fibrin-associated diffuse large B-cell lymphoma

Additional heart tumor articles (on DoveMed) that are not part of WHO Classification of Thoracic Tumors:

Angiomyolipoma of Heart: It is an extremely uncommon extrarenal angiomyolipoma that may be present in adult men and women. An angiomyolipoma is a benign tumor that is a mixture of blood vessels, smooth muscles, and fat.

Cardiac Fibrosarcoma: It is a very rare, high-grade malignancy of the heart. It is a form of sarcoma of the heart that is observed in adults of a wide age range.

Cardiac Myxosarcoma: It is a very rare, high-grade malignancy of the heart. It is a form of sarcoma of the heart. The tumors are observed in adults of a wide age range.

Cardiac Rhabdomyosarcoma: It is a very uncommon, high-grade malignant tumor of the heart. It is a primary tumor that originates within the heart and is observed in children and young adults.

Inflammatory Myofibroblastic Tumor of Heart: It is a very rare and mostly benign tumor of the heart. The tumor can grow to large sizes and generally occur in younger populations.

Lymphoma of Heart: It is a rare, B-cell non-Hodgkin’s lymphoma. The malignancy is generally aggressive and may affect children and adults over a wide age range.

Myxoid Malignant Fibrous Histiocytoma of Heart: It is a high-grade malignancy of the heart. A malignant fibrous histiocytoma is one of the most common sarcoma affecting the heart. The tumor usually develops in adults

Pleomorphic Malignant Fibrous Histiocytoma of Heart: It is a high-grade malignancy of the heart. A malignant fibrous histiocytoma is one of the most common sarcoma affecting the heart. The tumors are mostly observed in middle-aged adults.

Primary Cardiac Epithelioid Hemangioendothelioma: It is a low-grade malignant tumor that is extremely rare. The tumor may occur as a single mass or multiple masses and may affect individuals of any age category.

Synovial Sarcoma of Heart: It is an extremely rare malignancy of the heart. It is a primary tumor that originates within the heart. The tumor mostly forms in young and middle-aged adults.