Hydrops
The smaller tumors will typically grow in proportion to the baby. A large tumor may grow faster than the baby and can block blood flow to and/or from the heart. This blockage to blood flow can result in heart failure and the development of hydrops.
Hydrops or non-immune hydrops is a condition in which fluid collects in at least two body cavities. The areas where fluid can collect include:
- The space around the heart and/or lungs
- In the abdomen
- Under the skin
- In the scalp
It also can cause generalized swelling.
The presence of hydrops usually means a baby is at high risk for a poor outcome. Experts estimate that 50 to 98 percent of children with hydrops will not survive. This depends upon the age at which hydrops develops, why it developed and where the fluid has collected.
Cardiac Arrhythmias
An arrhythmia is an abnormal heart rate. There are different types of arrhythmias. About 20 percent of babies with rhabdomyomas have this complication. Arrhythmias develop when the tumors are close to an electrical conduction area of the heart.
Tuberous Sclerosis (TS)
The biggest concern when a rhabdomyoma is seen on prenatal ultrasound is the link between these tumors and tuberous sclerosis. TS is also called tuberous sclerosis complex (TSC). The name comes from the tubers or root-like growths of the brain that calcify with age and will become hard, or sclerotic.
Tuberous sclerosis is a neurocutaneous disorder. "Neuro" refers to neurologic issues that have to do with the brain, spine, and peripheral nerves (in the arms and legs). "Cutaneous" refers to the skin. Skin lesions are the most common symptom of this disorder.
Some studies suggest the link between rhabdomyomas and TS to be as high as 80 percent. Up to 50 percent of these cases have a familial occurrence. This means one or both parents may discover they have a very mild form of TS. In some cases, a parent will be diagnosed with tuberous sclerosis after his or her baby is.
Tuberous sclerosis is an autosomal dominant condition. Autosomal means both males and females are affected equally. Dominant means that only one parent would need to contribute the gene for TS in order for it to occur. A parent with TS has a 50/50 chance of having a child with TS.
For the remaining 50 percent of patients, TS is caused by a new mutation, and no other cases in the family will be discovered. However, parents of these children still may be at an increased risk for having another child with TS.