Summary about Disease
Fetal rhabdomyoma is a rare, benign (non-cancerous) tumor that arises from striated (skeletal or cardiac) muscle cells. These tumors are most commonly found in the heart (cardiac rhabdomyomas) and are often diagnosed prenatally or in early infancy. While the tumors themselves are not cancerous, they can cause complications depending on their size and location, particularly by obstructing blood flow in the heart. They are often associated with Tuberous Sclerosis Complex (TSC), a genetic disorder that can cause tumors to grow in various organs.
Symptoms
Symptoms vary depending on the size and location of the rhabdomyoma. In the case of cardiac rhabdomyomas, symptoms may include:
Prenatally: Fetal arrhythmia (irregular heartbeat), hydrops fetalis (fluid accumulation in the fetus).
Postnatally: Heart murmur, cyanosis (bluish skin discoloration due to low oxygen), shortness of breath, congestive heart failure, and in rare cases, sudden death.
Symptoms related to TSC such as seizures, developmental delays or skin abnormalities might also be present.
Causes
The primary cause of fetal rhabdomyomas, especially cardiac rhabdomyomas, is genetic mutations in the TSC1 or TSC2 genes. These genes are responsible for producing proteins (hamartin and tuberin, respectively) that regulate cell growth and proliferation. Mutations in these genes lead to uncontrolled cell growth, resulting in tumor formation. Most cases of fetal rhabdomyoma are associated with Tuberous Sclerosis Complex (TSC), a genetic disorder affecting multiple organ systems. However, sporadic (non-inherited) rhabdomyomas can occur in rare instances.
Medicine Used
There is no specific medicine to directly "cure" rhabdomyomas. Treatment focuses on managing the symptoms and complications they cause.
Medications for Heart Failure: Diuretics (to reduce fluid overload), ACE inhibitors or beta-blockers (to improve heart function) may be used.
Antiarrhythmic Drugs: Medications to control irregular heartbeats.
mTOR inhibitors: In some cases, especially in the context of TSC, mTOR inhibitors (like everolimus or sirolimus) may be used to reduce the size of the tumors.
Medications to control seizures
Is Communicable
No, fetal rhabdomyoma is not communicable. It is a genetic disorder or a result of spontaneous genetic mutation and cannot be transmitted from person to person.
Precautions
There are no specific precautions to prevent fetal rhabdomyoma since it's primarily a genetic condition. If there is a family history of Tuberous Sclerosis Complex (TSC), genetic counseling is recommended prior to conception to assess the risk of the child inheriting the condition. Regular prenatal ultrasounds can help in early detection of fetal abnormalities, including cardiac rhabdomyomas. If the child has been diagnosed with Rhabdomyoma, precautions should be taken to attend regularly scheduled checkups with a specialist.
How long does an outbreak last?
Rhabdomyoma is a tumor, not an "outbreak" of an infectious disease. If left untreated, the presence of the tumor may persist, and its effects on the body can be long-lasting. Cardiac rhabdomyomas often regress spontaneously during childhood, however, regular monitoring to observe regression or growth is imperative. The presence of TSC is permanent and ongoing.
How is it diagnosed?
Prenatal Ultrasound: Can detect cardiac rhabdomyomas during routine prenatal screenings.
Fetal Echocardiogram: Provides a detailed image of the fetal heart to confirm the diagnosis and assess the size and location of the tumor(s).
Postnatal Echocardiogram: Used to evaluate the heart after birth.
MRI or CT Scan: May be used to assess tumors in other organs.
Genetic Testing: To confirm the presence of TSC1 or TSC2 gene mutations, especially if Tuberous Sclerosis Complex is suspected.
Timeline of Symptoms
Prenatal: Detection of heart tumor via ultrasound, fetal arrhythmia, hydrops fetalis.
Infancy: Heart murmur, cyanosis, shortness of breath, feeding difficulties, seizures (especially in cases of TSC), developmental delays.
Childhood: Symptoms may improve spontaneously as tumors regress, but monitoring for complications related to TSC (e.g., developmental delays, seizures, skin lesions) is essential.
Important Considerations
Association with Tuberous Sclerosis Complex (TSC): A significant proportion of individuals with cardiac rhabdomyomas also have TSC. Thorough evaluation for TSC is essential in any child diagnosed with fetal rhabdomyoma.
Spontaneous Regression: Cardiac rhabdomyomas often regress spontaneously during childhood, but regular monitoring is still necessary.
Multidisciplinary Care: Management requires a team including cardiologists, neurologists, geneticists, and other specialists.
Genetic Counseling: Important for families with a history of TSC to understand the risk of recurrence in future pregnancies.
Long-term Follow-up: Even if the rhabdomyoma regresses, long-term monitoring for complications related to TSC is essential.