Primary tumors of the heart are extremely rare

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s that arise from the normal tissues that make up the

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...

. The incidence of primary cardiac tumors has been found to be approximately 0.02%. This is in contrast to secondary tumors of the heart, which are typically either

metastatic Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

from another part of the body, or infiltrate the heart via direct extension from the surrounding tissues. Metastatic tumors to the heart are about 20 times more common than primary cardiac tumors.

Types

Benign

The most common primary tumor of the heart is the

myxoma A myxoma (New Latin from Greek 'muxa' for mucus) is a myxoid tumor of primitive connective tissue. It is most commonly found in the heart (and is the most common primary tumor of the heart in adults) but can also occur in other locations. Ty ...

. In surgical series, the myxoma makes up as much as 77% of all primary tumors of the heart. Less common tumors of the heart include: *

Lipoma A lipoma is a benign tumor made of fat tissue. They are generally soft to the touch, movable, and painless. They usually occur just under the skin, but occasionally may be deeper. Most are less than in size. Common locations include upper back, ...

Rhabdomyoma A rhabdomyoma is a benign tumor of striated muscle. Rhabdomyomas may be either "cardiac" or "extra cardiac" (occurring outside the heart). Extracardiac forms of rhabdomyoma are sub classified into three distinct types: adult type, fetal type, and g ...

* Cystic tumor of the atrioventricular nodal region. * Lipomas and Lipomatous Hypertrophy of the

interatrial septum The interatrial septum is the wall of tissue that separates the right and left atria of the heart. Structure The interatrial septum is a that lies between the left atrium and right atrium of the human heart. The interatrial septum lies at angl ...

: the second most frequent primary cardiac tumor, usually located in the subepicardium *

Papillary Fibroelastoma A papillary fibroelastoma is a primary tumor of the heart that typically involves one of the valves of the heart. Papillary fibroelastomas, while considered uncommon, make up about 10 percent of all primary tumors of the heart. They are the third ...

Fibroma Fibromas are benign tumors that are composed of fibrous or connective tissue. They can grow in all organs, arising from mesenchyme tissue. The term "fibroblastic" or "fibromatous" is used to describe tumors of the fibrous connective tissue. Whe ...

Teratoma A teratoma is a tumor made up of several different types of tissue, such as hair, muscle, teeth, or bone. Teratomata typically form in the ovary, testicle, or coccyx. Symptoms Symptoms may be minimal if the tumor is small. A testicular terato ...

Malignant

About 20 percent of primary tumors of the heart are malignant in nature. Malignant tumors of the heart include

rhabdomyosarcoma Rhabdomyosarcoma (RMS) is a highly aggressive form of cancer that develops from mesenchymal cells that have failed to fully differentiate into myocytes of skeletal muscle. Cells of the tumor are identified as rhabdomyoblasts. There are four subt ...

angiosarcoma Angiosarcoma is a rare and aggressive cancer that starts in the endothelial cells that line the walls of blood vessels or lymphatic vessels. Since they are made from vascular lining, they can appear anywhere and at any age, but older people are ...

myxosarcoma Myxosarcoma is a rare malignant tumor of the heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, whil ...

fibrosarcoma Fibrosarcoma (fibroblastic sarcoma) is a malignant mesenchymal tumour derived from fibrous connective tissue and characterized by the presence of immature proliferating fibroblasts or undifferentiated anaplastic spindle cells in a storiform patte ...

leiomyosarcoma Leiomyosarcoma is a malignant (cancerous) smooth muscle tumor. A benign tumor originating from the same tissue is termed leiomyoma. While leiomyosarcomas are not thought to arise from leiomyomas, some leiomyoma variants' classification is evolvi ...

reticulum cell sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal ( connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sarc ...

desmoplastic small round cell tumor Desmoplastic small-round-cell tumor (DSRCT) is an aggressive and rare cancer that primarily occurs as masses in the abdomen. Other areas affected may include the lymph nodes, the lining of the abdomen, diaphragm, spleen, liver, chest wall, skull, ...

, and

liposarcoma Liposarcomas are the most common subtype of soft tissue sarcomas, accounting for at least 20% of all sarcomas in adults. Soft tissue sarcomas are rare neoplasms with over 150 different histological subtypes or forms. Liposarcomas arise from the pr ...

s. Angiosarcoma is the most common primary cardiac malignancy. It tends to occur in the right atrium and involve the pericardium. Cardiac sarcomas may occur at any age but are more commonly seen in individuals in their 20s to 40s. They occur equally in males and females. Rhabdomyosarcoma is the most common primary cardiac malignancy in children and is more likely than other primary cardiac sarcomas to involve the valves.

Valvular

A subset of the primary tumors of the heart are tumors that are found on the valves of the heart. Tumors that affect the valves of the heart are found in an equal distribution among the four heart valves. The vast majority of these are

papillary fibroelastoma A papillary fibroelastoma is a primary tumor of the heart that typically involves one of the valves of the heart. Papillary fibroelastomas, while considered uncommon, make up about 10 percent of all primary tumors of the heart. They are the third ...

s. Primary tumors of the valves of the heart are more likely to occur in males. While most primary tumors of the valves of the heart are not malignant, they are more likely to have symptoms related to the valve, including neurologic symptoms and (in a few cases)

sudden cardiac death Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...

Clinical manifestations

In general, tumors might manifest in one of three ways: Systemic symptoms include constitutional symptoms(fever, arthralgias, weight loss, weariness) and paraneoplastic disorders (PCTs). Cardiovascular symptoms: mass effect compromising myocardial function or blood flow, causing arrhythmias, obstruction of heart valves leading to regurgitation, or pericardial effusion with or without tamponade. Primary symptoms include breathlessness, chest pain, presyncope, and syncope. Thromboembolic symptoms: lung and systemic thromboembolic condition resulting from the tumor. Symptoms caused by primary cardiac tumors are usually dependent on size and location. Cardiac tumors can cause a variety of symptoms. The mass size can obstruct blood flow or interfere with cardiac valve function and produce symptoms of heart failure. A tumor that invades the heart walls may cause arrhythmias, heart block, or pericardial effusion with or without tamponade. Tumors that invade adjacent lung tissue may cause pulmonary symptoms that mimic bronchogenic carcinoma. The tumor may break apart and can embolize. Embolization can be systemic or pulmonic. Tumors with the highest anatomic risk for embolization are located in the left atrium or aortic valve. Some tumors produce no symptoms and are incidentally found. Systemic symptoms Primary cardiac tumors may secrete factors including

interleukin-6 Interleukin 6 (IL-6) is an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. In humans, it is encoded by the ''IL6'' gene. In addition, osteoblasts secrete IL-6 to stimulate osteoclast formation. Smooth ...

and

endothelin Endothelins are peptides with receptor (biochemistry), receptors and effects in many body organs. Endothelin constricts blood vessels and raises blood pressure. The endothelins are normally kept in balance by other mechanisms, but when gene ex ...

. This may contribute to systemic inflammatory or autoimmune manifestations. Systemic symptoms including fever, fatigue, arthralgia, anemia, elevated white blood cell count, thrombocytosis, thrombocytopenia, hypergammaglobulinemia, and elevated erythrocyte sedimentation rate. Myxomas have been found to produce vascular endothelial growth factor, which contributes to the development of new blood vessels and the early stages of tumor growth.

Diagnostic evaluation

The initial diagnostic evaluation is to determine whether or not a cardiac tumor is present, the location of the tumor, and if the tumor is benign or malignant. Initial imaging is often performed by echocardiography. Benign lesions have a distinct appearance on an echocardiogram. An echocardiogram can identify the presence of a mass and its mobility. The echocardiogram can also identify a mass causing obstruction of circulation. The echocardiogram can provide accurate information as to whether the tumor is malignant or benign. Cardiac magnetic resonance imaging can identify the chemical microenvironment within the tumor, thus providing more information as to the type of tumor present. Cardiac computed tomography is useful when MRI is unavailable or contraindicated. Coronary angiography is used to identify the blood supply to cardiac tumors.

Treatment and prognosis

The vast majority of the tumors of the heart have a benign course and are not directly fatal. However, even the benign tumors of the heart can be lethal due to either direct extension into the electrical conduction system of the heart (causing

complete heart block Third-degree atrioventricular block (AV block) is a medical condition in which the electrical impulse generated in the sinoatrial node (SA node) in the atrium of the heart can not propagate to the ventricles. Because the impulse is blocked, an a ...

or a fatal dysrhythmia), or due to

emboli An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule ( fat embolism), a bubble of air or other gas (gas embolism), amniotic fluid (amniot ...

from the tumor mass that may have lethal sequelae. Prompt resection is indicated for myxomas due to the risk of embolization or cardiovascular complications. Close observation has also been suggested for cardiac tumors that are small (<1 cm) and non-mobile. The malignant tumors of the heart have a worse prognosis. Cardiac sarcomas generally lead to death within 2 years of diagnosis, due to rapid infiltration of the myocardium of the heart and obstruction of the normal flow of blood within the heart.

References

{{Heart and thymus neoplasia Heart neoplasia