Familial Atrial Myxoma

Atrial myxoma is the most common primary heart tumor. It usually is nonmalignant and sporadic, but 10% are familial.

Atrial Myxoma; Intracardiac Myxoma.

Cardiac myxomas account for 40 to 50% of primary cardiac tumors. They are solitary and pedunculated and usually involve only the left atrium in the nonfamilial form (90% of cases) and both sides of the heart in the familial form (10% of atrial myxomas). In the sporadic cases, the female-to-male ratio is 3:1, whereas both sexes are equally involved in the familial cases. The overall prevalence of primary cardiac tumors is approximately 0.02% (200 tumors per one million autopsies); approximately 37.5% of them are myxomas (75 cases of myxoma per one million autopsies).

In cases of familial occurrence (10% of atrial myxomas), the transmission is autosomal dominant.

The tumor is benign but can be lethal if it obstructs a valve or causes major embolic events. It arises from the epithelium and acts as a space-occupying lesion. A left atrial lesion behaves as a mitral valve stenosis and leads to pulmonary edema, whereas a right atrial lesion acts as a tricuspid valve stenosis and manifests with dyspnea and hypoxemia. These tumors are friable, resulting in tumor embolism that occurs in approximately 30 to 40% of patients. Symptomatology depends on the location of the tumor (left or right atrium) and the presence of an intracardiac shunt.

Confirmed by an echocardiogram in suspected cases.

Symptoms are produced by mechanical interference with cardiac function or embolization. It seems that familial disease involves younger patients with more frequent lesions on the right side of the heart and more recurrences over the years. Complications associated with the disease, such as vascular aneurysms, are not more common in the familial cases.

An echocardiogram and ECG are needed preoperatively to document the extent and number of lesions and their effect on the hemodynamics of the heart. An angiogram should be part of the workup to rule out the presence of vascular aneurysms in the cerebral, coronary, and pulmonary vasculature. If the syndrome form is suspected, rule out involvement of the adrenals.

Affected patients present with lesions that can obstruct cardiac valves and thus decrease cardiac output considerably. Consider avoiding use of medication with the potential to depress myocardial function (especially contractility), prevent tachycardia, and maintain adequate preload. In the case of right-sided lesions, use of a central line in the superior vena cava should be assessed carefully.

No specific implications reported for this condition.

In familial cases, atrial myxoma can be isolated or occasionally is associated with other disorders, constituting distinct entities.

Carney Complex Type I: Multiple neoplasia syndrome characterized by spotty skin pigmentation, cardiac and other myxomas organs (e.g., breast, skin, thyroid gland, neural tissue), endocrine tumors, and psammomatous melanotic schwannomas. Clinical features include lentigines (brown discoloration of skin) and pigmented nevi, pituitary overactivity (Cushing syndrome), ventricular myxoma, subcutaneous myxoid neurofibromata, and mammary fibroadenosis. Hirsutism and spotty facial and labial (female) pigmentation are characteristics of this medical condition. Severe atherosclerotic narrowing of the left anterior descending coronary artery has been reported as the cause of death in a 44-year-old man following surgical hernioplasty. NAME (nevi, atrial myxoma, myxoid neurofibroma, and ephelides [tanned skin macules]) syndrome and LAMB (lentigines, atrial myxoma, and blue nevi) syndrome now are considered under the group of Carney complex.