Atrial Myxoma

By : DR NABAJYOTI HAZARIKACTVS Deptt., Gauhati Medical College & Hospital,

Guwahati, Assam, India

ATRIAL MYXOMAS

Myxomas are one of the most benign neoplasm which comprise 50%

out of which 15% myxomas are observed in children

INTRODUCTION

5% of myxoma patients show a familial pattern of tumor development based on autosomal dominant inheritance. These patients and 20% of those with sporadic myxoma have an abnormal DNA genotype chromosomal pattern.

In contrast to the “typical” sporadic myxoma profile, familial patients are more likely to be younger, equally likely to be male or female, and more often (22%) have multicentric tumors originating from either the atrium or ventricle.

Familial myxomas have the same histology, they have a higher recurrence rate after surgical resection (21 to 67%). Approximately 20% of familial patients have associated conditions such as adrenocortical nodule hyperplasia, Sertoli cell tumors of the testes, pituitary tumors, multiple myxoid breast fibroadenomas, cutaneous myomas, and facial or labial pigmented spots. These conditions often are described as complex myxomas within the group of familial myxoma. A familial syndrome with autosomal X-linked inheritance characterized by primary pigmented nodular adrenocortical disease with hypercortisolism, cutaneous pigmentous lentigines, and cardiac myxoma is referred to as Carney’s complex.

A series of six atrial tumors, with characteristics we now recognize as myxoma, was published in 1845 by King.

The first echocardiographic diagnosis of an intracardiac tumor was made in 1959.

An intracardiac myxoma was diagnosed by angiography in 1952 by Goldberg, but attempts at surgical removal were unsuccessful.

Treatment of cardiac tumors was profoundly influenced by two events: the introduction of cardiopulmonary bypass in 1953 by John Gibbon, which allowed a safe and reproducible approach to the cardiac chambers, and the introduction of cardiac echocardiography, which allowed safe and noninvasive diagnosis of an intracardiac mass.

HISTORY

A large right atrial myxoma was removed by Bhanson in 1952 using caval inflow occlusion, but the patient died 24 days later.

Crafoord in Sweden first successfully removed a left atrial myxoma in 1954 using cardiopulmonary bypass, and Kay in Los Angeles first removed a left ventricular myxoma in 1959.

By 1964, 60 atrial myxomas had been removed successfully, with improved results owing to the increasing safety of cardiopulmonary bypass and use of echocardiography for detection.

CLASSIFICATION

*familial syndrome with autosomal X-linked inheritance characterized by primary pigmented nodular adrenocortical disease with hypercortisolism, cutaneous pigmentous lentigines, and cardiac myxoma is referred to as Carney’s complex.

Both biatrial and multicentric myxomas are more common in familial disease. Biatrial tumors probably arise from bidirectional growth of a tumor originating within the atrial septum. Atrial myxomas generally arise from the interatrial septum at the border of the fossa ovalis but can originate anywhere within the atrium, including the appendage.

In addition, isolated reports confirm that myxomas can arise from the cardiac valves, pulmonary artery and vein, and vena cava.

PATHOLOGY

Right atrial myxomas are more likely to have broad-based attachments than left atrial tumors; they also are more likely to be calcified, and thus visible on chest radiographs.

Ventricular myxomas occur more often in women and children and may be multicentric. Right ventricular tumors typically arise from the free wall, and left ventricular tumors tend to originate in the proximity of the posterior papillary muscle.

two-thirds of myxomas are round or oval tumors with a smooth or lobulated surface. Most are polypoid, compact, pedunculated, mobile, and not likely to fragment spontaneously.

Less common villous or papillary myxomas are gelatinous and fragile and prone to fragmentation and embolization, occurring about one-third of the time.

Myxomas arewhite,yellow, or brown in color, andfrequently covered with thrombus.Focal areas of hemorrhage,cyst formation, ornecrosis

The average size is about 5 cm in diameter, but growth to 15 cm in diameter and larger has been reported.

Myxomatous tumors appear to grow rapidly, but growth rates vary, and occasionally, tumor growth arrests spontaneously. Weights range from 8 to 175 g, with a mean between 50 and 60 g.

Histologically, myxomas are composed of polygonal-shaped cells and capillary channels within an acid mucopolysaccharide matrix. The cells appear singularly or in small clusters throughout the matrix, and mitoses are rare.

Ten percent of the tumors have microscopic deposits of calcium and metastatic bone deposits, as well as sometimes glandular-like structure.

Myxomas arise from the endocardium and are considered derivative of the subendocardial multipotential mesenchymal cell.

Occasional presence of hematopoietic tissue and bone in these tumors. Interestingly, myxomas have developed after cardiac trauma, including repair of atrial septal defects and trans-septal puncture for percutaneous dilatation of the mitral valve.

The classic clinical presentation of a myxoma is intracardiac obstruction with congestive heart failure (67%);

Signs of embolization (29%); systemic or constitutional symptoms of fever (19%); weight loss or fatigue (17%);

Immunologic manifestations of myalgia, weakness,

Arthralgia (5%). Cardiac rhythm disturbances and infection occur less frequently.

CLINICAL PRESENTATION

Nearly all myxoma patients admit to a variety of constitutional symptoms. These symptoms may be accompanied by

weakness of one side of the body,bylateral weakness,stroke on evolution or stroke,a leukocytosis,elevated erythrocyte levels and sedimentation rate,hemolytic anemia,thrombocytopenia,elevated C-reactive protein.Immunoelectrophoresis may reveal abnormal immunoglobulin levelswith increased circulating IgG.elevated levels of interleukin-6

CONSTITUTIONAL SYMPTOMS

associated conditions are -including lymphadenopathy,tumor metastasis,ventricular hypertrophy,development of constitutional symptoms.Other less frequent complaints include

Raynaud’sphenomenon,arthralgias, myalgias,erythematous rash,clubbing of the digits.

Possible etiologies of such varied complaints and symptoms include -

tumor embolization with secondary myalgiasarthralgias,elevated immunoglobulin response.Circulating antibody–tumor antigencomplexes with complement activation alsomay play a role.

OBSTRUCTION Obstruction of blood flow in the heart is the most common cause of

acute presenting symptoms. The nature of these symptoms is determined by which of the chambers is involved and the size of the tumor.

Myxomas in the left atrium tend to mimic mitral disease. These produce positional dyspnea and other signs and symptoms of heart failure associated with elevated left atrial and pulmonary venous pressures.

Clinically, mitral stenosis often is suspected and leads to echocardiography and diagnosis of myxoma. Syncopal episodes occur in some patients and are thought to result from temporary occlusion of the mitral orifice.

Right atrial myxomas can produce a clinical picture of right-sided heart failure with signs and symptoms of venous hypertension, including hepatomegaly, ascites, and dependent edema and can cause tricuspid valve stenosis by partially obstructing the orifice.

If a patent foramen ovale is present, right-to-left atrial shunting may occur with central cyanosis, and paradoxical embolization has been reported.

Systemic embolization is the second most common mode of myxomatous presentation, occurring in 30 to 40%

Because the majority of myxomas are leftsided, approximately 50% of embolic episodes affect the central nervous system owing to both intra and extracranial vascular obstruction.

Neurologic deficits may present as –seizures,hemiparesis, andbrain necrosis.

EMBOLIZATION

Retinal artery embolization with visual loss has occurred in some patients.

Embolic myxomatous material may cause –blocking iliac,femoral arteries, andsometimes visceras also

Right-sided myxomatous emboli mainly obstruct pulmonary arteries and cause pulmonary hypertension and even death from acute obstruction.

Infection arising in a myxoma is a rare

If occurs urgent surgical intervention is required

INFECTION

Clinical examination

“tumor plop” and unpredictable sign and symptoms during auscultation apart from other general examinations which includes physical examination etc.

Chest Radiograph and Electrocardiogram

DIAGNOSIS

Nonspecific abnormalities such as chamber enlargement, cardiomegaly, bundle-branch blocks, and axis deviation can be found. Fewer than 20% of patients have atrial fibrillation. Evaluation of nonspecific electrocardiographic abnormalities occasionally leads to an incidental diagnosis of myxoma most electrocardiograms are not helpful in establishing a diagnosis.

Cross-sectional echocardiography is the most useful test employed for the diagnosis and evaluation of myxoma. The sensitivity of two-dimensional (2-D) echocardiography for myxoma is 100%.

this imaging technique largely has supplanted angiocardiography.

coronary angiography. Transesophageal echocardiography (TEE) CT SCAN and MRI

Surgical resection is the only effective therapeutic option for patients with cardiac myxoma and should not be delayed because death from obstruction to flow within the heart or embolization may occur in as many as 8% of patients awaiting operation.

A median sternotomy approach with ascending aortic and bicaval cannulation usually is employed.

Manipulation of the heart before initiation of cardiopulmonary bypass is minimized in deference to the known friability and embolic tendency of myxomas.

CPB management.

SURGICAL MANAGEMENT

1. Smith C: Tumors of the heart. Arch Pathol Lab Med 1986; 110:371.

2. McAllister HA, Fenoglio JJ Jr: Tumors of the cardiovascular system, in Atlas of Tumor Pathology, Series 2. Washington, DC, Armed Forces Institute of Pathology, 1978.

3. Straus R, Merliss R: Primary tumors of the heart. Arch Pathol 1945; 39:74.

4. Reynen K: Cardiac myxomas. N Engl J Med 1995; 333:1610.

5. Wold LE, Lie JT: Cardiac myxomas: a clinicopathologic profile. Am J Pathol 1980; 101:219.

6. Silverman NA: Primary cardiac tumors. Ann Surg 1980; 91:127.

LITERATURE (ADDENDUM)

Experiences in Our center & Surgical

Intervention

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