CARDIAC FIBROMA

CARDIAC MYXOMA

CARDIAC FIBROMA

Cardiac fibromas are more commonly seen in infants and young children with only a two cases that were antenatally detected (1,2).

Histologically these are non-encapsulated tumors that tend to blend with the normal myocardial tissue.

ULTRASOUND

• Echogenic mass arising from the interventricular septum and the free wall of the left ventricle (diagnosed at 20 weeks gestation) (1), or right ventricle (diagnosed at 35 weeks, with normal scans at 13 and 21 weeks) (2).
• Usually solitary and intramural.

• Hypoplasia of the left ventricle and ascending aorta from early outflow obstruction (1).
• Slow growth is characteristic (unlike rhabdomyomas which may disappear)
• They may grow to a large size and undergo central necrosis and calcification.
• Arrhythmias, cardiovascular collapse or sudden death has been reported in infants (3). Doppler studies may help assess the hemodynamic significance of the lesion.
• Fetal hydrops and pericardial effusion, although not yet reported in fetal cardiac fibromas may occur with any cardiac tumor depending on its anatomic location and size of the tumor.

ASSOCIATIONS

• Cystic renal dysplasia (4).
• Gorlin's syndrome (nevoid basal cell carcinoma syndrome (5).

CARDIAC MYXOMA

Although cardiac myxomas are the most common primary cardiac tumor in adults (6), they are exceedingly rare in the neonate (7,8).

• They arise from the endocardium (75% in the left atrium and 25% in the right atrium) (9,10).
• They are usually single and attach to the fossa ovalis by a pedicle. Attachment to the left atrial free wall has been reported (11).

The classical appearance is that of a large pedunculated tumor that traverses back and forth through the atrio-ventricular valve (12,13).

• They are benign but have a tendency for local recurrence, and rarely malignant degeneration (14).
• 90% are sporadic. Increased frequency in patients with multiple lentigines syndrome (also have pigmented skin lesions and

endocrine neoplasm’s (15).

• Complications include obstruction of the atrio-ventricular valve and pulmonary venous inflow (7,9).

In the neonate they have been reported causing RV failure and sudden neonatal death (7).

Cardiac myxomas in the right atrium.

The tumor arises from the wall of the RA

and is on a pedicle. Note how the tumor prolapsed through the atrioventricular valve during the normal cardiac cycle, but there is no significant obstruction present.

REFERENCES

1. Malisch TW, Jeanty P. Cardiac fibroma. Fetus 1991;1:1.
2. Munoz H, Sherer DM, Romero R et.al. Prenatal sonographic findings of a large fetal cardiac fibroma. J Ultrasound Med 1995;14:479-481.
3. Reece IJ, Houston AB, Poolock JCS. Interventricular fibroma: Echocardiographic diagnosis and successful removal in infancy. Br Heart J 1983;50:590.
4. Schwartz J, Saldivar V, Tio F et.al. Interventricular fibroma and cystic renal dysplasia in a newborn. Pediatr Pathol 1984;2:187.
5. Coffin CM. Congenital cardiac fibroma associated with Gorlin's syndrome. Pediatr Pathol 1992;12:255.
6. McAllister HA Jr. Primary tumors of the heart and pericardium. Pathol Annu 1979;14:325-355.
7. Dianzumba SS, Char G. Large calcified right atrial myxomas in a newborn: are cause of neonatal death. Br Heart J 1982;48:177-179.
8. Butto F, Shachar GB, Najmabadi H et.al. Massive cardiac tumor presenting as sever cyanosis in the newborn. Pediatr Cardiol 1994;15:103-105.
9. Osano M, Yashiro K, Oikawa T et.al. Intramural fibroma of the heart: A case report. Pediatrics 1969;43:605-608.
10. Crawford FA, Selby JH, Watson D et.al. Unusual aspects of atrial myxomas. Ann Surg 1978;188:240-244.
11. Johnson ML, Sieker HO, Behar VS et.al. echocardiographic diagnosis of left atrial myxomas found attached to the free left atrial wall. Ann Surg 1978;188:240-244.
12. Oetgen WJ, Umfrid RP III, Hamilton KM et.al. Two-dimensional echocardiography in the diagnosis of left atrial myxomas in a child. South Med J 1982;75:1125-1127.
13. Abramowitz R, Majdan JF, Plzak LF et.al. Two-dimensional echcardiographic diagnosis of separate myxomas of both the left atrium and left ventricle. Am J Cardiol 1984;53:379-380.
14. Read RC, White HJ, Murphy ML et.al. The malignant potentiality of left atrial myxomas. J Thorac Cardiovasc Surg 1974;68(6):857-868.
15. Robertson R. Primary cardiac tumors. Surgical treatment. Am J Surg 1957;94:183-193.