Los rhabdomiomas son tumores benignos del músculo estriado que se localizan con mayor frecuencia en la cabeza y cuello. Los rabdomiomas son extremadamente raros en los adultos, siendo mucho más frecuentes en la primera infancia, generalmente de carácter congénito. El rabdomioma cardíaco es el tumor cardiaco más común de la infancia presentándose en el 75% de los casos, antes del primer año. Se presenta en 1-2 casos/10.000 niños. Existe una clara asociación entre el rabdomioma cardíaco y la esclerosis tuberosa: aproximadamente el 40% de los pacientes con rabdomioma cardíaco presentan esclerosis tuberosa y, inversamente, el 50% de los casos de escletosis tuberosa muestran evidencias ecocardiográficas de rabdomiomas (*).

Las lesiones son a menudo múltiples y se originan desde el septum ventricular o desde las paredes de los ventrículos aunque, en un 30% de los casos, las aurículas están afectadas. Nunca afectan a las válvulas cardíacas.

Se desconoce la etiología. Los rabdomiomas se asemejan a los hamartomas en que derivan de mioblastos embriónicos de los que se produce una proliferación anormal de tejido dado lugar a uno o varios tumores sólidos, circunscritos, no encapsulados. Macroscópicamente son masas de color amarillo-tostado. Microscópicamente se caracterizan los presencia de vacuolas llenas de glucógeno (*)

The etiology is unknown. A rhabdomyoma resembles a hamartoma derived from embryonal myo­blasts in which there is an abnormal proliferation of tissue yielding single or multiple solid circumscribed, unencapsulated tumors of variable size. They may arise anywhere in the myocardium, most commonly the ventricle, but not from a valve, and may project into a cardiac chamber. Grossly the appear as yellow-tan solid, circumscribed, unencapsulated tumors. Microscopically, the characteristic spider cell is seen which is a large clear cell with cytoplasmic strands composed of glycogen extending to the plasma membrane.

s a benign striated muscle tumor that is usually classified as cardiac or extracardiac based on its location and unique histology. The adult extracardiac form of rhabdomyoma is extremely uncommon, with < 100 cases reported in clinical literature. 1 These lesions mostly occur in the head and neck. Cardiac rhabdomyoma is the most common cardiac tumor seen during infancy and childhood, with approximately 75% occurring prior to the age of 1 year. There is a well-described association with tuberous sclerosis, a familial multisystemic syndrome characterized by mental retardation, epilepsy, adenoma sebaceum, and hamartomas in multiple organs. About 40% of patients with pathologically confirmed cardiac rhabdomyoma s have tuberous sclerosis 2 ; conversely, up to 50% of patients with tuberous sclerosis have evidence of cardiac rhabdomyoma s on echocardiography. 3 The lesions of rhabdomyoma are often multiple and can originate from the ventricular septum or the free wall of either ventricle. The atria are involved in up to 30% of cases. Lesions are yellow-gray in appearance and although not encapsulated, are well circumscribed from surrounding tissue. The classic microscopic finding is the "spider cell," a large cell with a central cytoplasmic mass surrounded by fibrillar strands that give the appearance of a spider hanging in a net. 4