Rhabdomyoma is a rare benign tumor found in striated muscles.

It can be found within the heart or outside of the heart. Those found within the heart are called cardiac rhabdomyoma and those found outside the heart are called extracardiac rhabdomyoma.

There are three main types of extracardiac rhabdomyoma – adult, fetal and genital. Most adult rhabdomyoma occurs in middle-aged males. The tumors are frequently found in the head and neck area, particularly in the mouth.

Fetal extracardiac rhabdomyoma is often seen in the muscles of the face. Cardiac rhabdomyoma is the most common type of primary heart tumor seen in infants and children. With the sophistication in scanning equipment these are often identified in utero.

Rhabdomyoma tumors can present as single or multiple tumors. While the exact cause of rhabdomyoma is unknown it has been associated with sporadic cell mutations and congenital heart malformations. It is also believed to have genetic links. There is a strong association with genetic diseases such as tuberous sclerosis and Down syndrome. Rhabdomyoma do not generally spread and they can grow anywhere from 1mm up to 10cm.

Signs & Symptoms

While rhabdomyoma tumors do not cause symptoms on their own, they cause problems when they start to interfere with the organs around them. Particularly in cardiac rhabdomyoma the tumors can grow so much that they begin to block the chambers of the heart. This can lead to loss of blood flow and other serious complications, including death.

Diagnosis

Since rhabdomyoma is such a rare cancer diagnosis can take some time. As with other cancers doctors perform a physical exam and ask about family history. They will then do imaging tests and a biopsy.

Treatment

Rhabdomyoma is most often treated with surgery. Complete or partial removal of the tumor can often relieve problems being caused by the tumor. It is very rarely reported that rhabdomyoma becomes malignant and recurrence is rare.

Prognosis

Prognosis of rhabdomyoma depends largely on the size and location of the tumor. For cardiac rhabdomyoma there is an 81% – 92% survival rate due to the ability of doctors to successfully remove the tumor. At the other end of the spectrum, tumors that have grown above 20cm in size are associated with death since the heart’s chambers can become fully blocked.