Cardiac rhabdomyomas and obstructive left heart disease: histologically but not functionally benign.

Background: Cardiac rhabdomyoma is the most common primary heart tumor in infants. Spontaneous regression of such tumors is common, particularly with smaller lesions, followed by resolution of symptoms. Based on our data on spontaneous involution, our institutional philosophy has been one of expectant management in the absence of life-threatening symptoms. However, surgical intervention sometimes is required for the extirpation of a rhabdomyoma from the left ventricular outflow tract.

Methods: A retrospective review was conducted of 30 children in whom a rhabdomyoma was diagnosed over a 27-year period.

Results: Twenty-three percent (7/30) of the children required surgical extirpation of the tumor from within their left ventricular outflow tract, although a total of 94% had left ventricular involvement. There were no deaths. To date, no child has required reexcision of tumor.

Conclusions: The natural history of rhabdomyoma is one of spontaneous regression (the 23 children who did not undergo surgical intervention are alive and continue to be followed up medically). We recommend surgical excision to alleviate acute outflow tract obstruction with reliance on the tumor's natural history of regression to achieve long-term freedom from reoperation. Although operation has been recognized as lifesaving, we were somewhat surprised to find that greater than 20% of our pediatric population required operative intervention.