What are the other Names for this Condition? (Also known as/Synonyms)

• Central Nervous System Rhabdoid Neoplasm - Atypical Teratoid/Rhabdoid Tumor
• Malignant Brain Rhabdoid Neoplasm - Atypical Teratoid/Rhabdoid Tumor
• Rhabdoid Tumor of CNS - Atypical Teratoid/Rhabdoid Tumor

What is Atypical Teratoid Rhabdoid Tumor? (Definition/Background Information)

• Atypical Teratoid/Rhabdoid Tumor (AT/RT or ATRT) is an infrequent, aggressive, highly malignant tumor, affecting the central nervous system (CNS) and brain of infants and very young children. The cell of origin of this tumor is unknown; defects on chromosome 22 are linked to AT/RT
• The signs and symptoms of the tumor include lethargy, headache, vomiting, paralysis on one side of the body, loss of balance, etc. AT/RT may be diagnosed using radiological scans, such as MRI and CT of brain; a tissue biopsy may help confirm the diagnosis, when possible
• Since the affected individuals are young children, and thus, radiation therapy is typically not considered as a treatment tool; chemotherapy and where possible, surgical excision with removal of the tumor, is employed
• Pediatric brain cancers are among the leading child mortality illnesses and with the highly malignant Atypical Teratoid/Rhabdoid Tumor, the survival rate is low (10-15%) for children below the age of 2 years. Hence, the prognosis is usually poor

Who gets Atypical Teratoid Rhabdoid Tumor? (Age and Sex Distribution)

• Infants and young children below the age of 3 years are normally affected by Atypical Teratoid/Rhabdoid Tumor. In some rare cases, older children and young adults have also been found to have AT/RT
• The tumor incidence in males is slightly higher than that in females (in a 3:2 ratio)
• About 1-2% of all children who are affected by brain tumors, have AT/RT
• Individuals of all races and ethnic groups can be affected

What are the Risk Factors for Atypical Teratoid Rhabdoid Tumor? (Predisposing Factors)

The risk factors of Atypical Teratoid/Rhabdoid Tumor include:

• Age of the child seems to be a strong feature of AT/RT; infants and very young children are commonly affected
• Considering the prevalence factor, a boy child has a higher risk than a girl child
• Some genetic predilection is observed; individuals having had close family members with AT/RT or other brain tumors are at risk

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Atypical Teratoid Rhabdoid Tumor? (Etiology)

• Cell study and genetic analysis have implicated anomalies in chromosome 22, combined with a loss of genetic material and gene mutation, as a primary factor for Atypical Teratoid/Rhabdoid Tumor occurrence. Many renal and soft tissue tumors in children, are also linked to this loss of genetic material, which is said to function as a tumor suppressor gene
• ATRT, affecting several regions of the brain and central nervous system (CNS), is characterized by rapid cell divisions. It has been documented that the tumor spreads along the cerebrospinal fluid conduits
• This CNS tumor (which is characterized by rapid and uncontrolled cell proliferation) has been analyzed as being composed of cells having a big, eccentric nucleus, with plenty of cytoplasm (cell substance, excluding the nucleus)

What are the Signs and Symptoms of Atypical Teratoid Rhabdoid Tumor?

The signs and symptoms of Atypical Teratoid/Rhabdoid Tumor depend on the age of the child and the exact location in the brain or central nervous system (CNS), where the tumor is located. These include:

• Lethargy, tiredness
• Headache
• Cranial nerve palsy
• Tilting of head
• Vomiting
• Paralysis of arm, leg, and trunk, on one side (half) of the body
• Unsteady walking posture, loss of balance
• Infants may have a large head (considering the body proportion)

How is Atypical Teratoid Rhabdoid Tumor Diagnosed?

Atypical Teratoid/Rhabdoid Tumor may be diagnosed using the following tools:

• Physical exam with family medical history evaluation
• MRI scan of the CNS (brain and spine)
• CT scan of the abdomen, chest
• Bone marrow aspiration and biopsy
• Bone scan
• Analysis of the cerebrospinal fluid using lumbar puncture
• When it is possible, a tissue biopsy may be performed to confirm the diagnosis

A differential diagnosis may be necessary to confirm AT/RT, as it significantly overlaps in appearance, with other embryonal tumors, like medulloblastoma (another brain tumor).

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Atypical Teratoid Rhabdoid Tumor?

A few complications of Atypical Teratoid/Rhabdoid Tumor could include:

• Metastasis and rapid dissemination of AT/RT to other locations of the brain and CNS (and even to the kidneys)
• Side effects of chemotherapy and radiation therapy: The long-term effects in children could include infertility, learning disabilities, lack of cognitive skills, etc.

How is Atypical Teratoid Rhabdoid Tumor Treated?

The treatment of Atypical Teratoid/Rhabdoid Tumor may involve:

• Chemotherapy combined with stem cell or bone marrow transplantation is effective to some extent in treating AT/RT
• Considering the young age of the affected population (less than 3 years) and the malignancy of the tumor, radiotherapy is not a safe option
• Surgical removal of the tumor is a critical option provided metastasis has not occurred; this is followed by chemotherapy. The size of the remaining portion of tumor after its surgical removal, is a key prognostic indicator
• New drugs and safer radiation techniques are still being developed and clinical trials progressing, to find effective ways to treat this pediatric brain tumor
• Post-operative care is important: A minimum activity level is to be ensured, until the surgical wound heals
• Follow-up care with regular screening and check-ups are important

How can Atypical Teratoid Rhabdoid Tumor be Prevented?

• Currently, there are no specific methods or guidelines to prevent Atypical Teratoid/Rhabdoid Tumor
• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• In order to avoid a relapse, or be prepared for a recurrence; the entire diagnosis, treatment process, drugs administered, etc. should be well-documented and follow-up measures initiated
• Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations, are mandatory for those who have been diagnosed with the tumor
• Due to both its metastasizing potential and chances of recurrence, often several years of active follow-up vigilance is necessary

What is the Prognosis of Atypical Teratoid Rhabdoid Tumor? (Outcomes/Resolutions)

• Ages of the child at diagnosis is an important factor governing the prognosis of Atypical Teratoid/Rhabdoid Tumor; children, aged 3 years and above, generally show a better survival rate (70%)
• Infants and children below the age of 3 years (at AT/RT diagnosis), have a high mortality rate. Patients with ATRT have a median survival period of less than 2 years
• Children with metastatic tumors and large-sized tumors have the worst outcomes
• Current treatment methods are inadequate; besides, Atypical Teratoid/Rhabdoid Tumor is also resistant to many drugs. This factor combined with its speedy recurrence, portrays a dismal prognosis for the affected children

Additional and Relevant Useful Information for Atypical Teratoid Rhabdoid Tumor:

• Palliative care is recommended by most pediatricians/oncologists when the prognosis is poor, particularly for infants and young children
• Atypical Teratoid/Rhabdoid Tumor is currently being researched upon and clinical trials are underway