Atypical Teratoid Rhabdoid Tumor

Introduction

An atypical teratoid rhabdoid tumor or AT/RT is one of the highly malignant neoplasm that occurs in the posterior fossa of children younger than three years of age. It can be present anywhere in the brain region. These tumors are likely to be aggressive and often spread through the CNS (Central Nervous System). Adult cases of atypical teratoid rhabdoid tumor are rare and only 27 cases with a diagnosis of either AT/RT have been reported so far.

These tumors are uncommon with an incidence rate of 2-3 percent of primary CNS tumors in children less than 18 years of age and there is a slight male dominance. Most patients’ age less than two years, however some older children and even adults with AT/RT have been reported.

Signs And Symptoms

Nearly half of the AT/RT develop in the posterior fossa, though the tumor is present throughout the nervous system. Patients with posterior fossa tumors frequently experience symptoms that are related to hydrocephalus such as morning headaches, lethargy, vomiting, etc. Such patients may build up ataxia or regression of the motor skills. Moreover, a rapidly enlarging size of the head may be the fundamental sign of a rapid growing tumor. In addition, with supratentorial, tumors can develop with signs and symptoms of hydrocephalus such as hemiparesis, seizures, or visual changes depending of the position of the tumors. Since AT/RT is a highly severe tumor, patients usually have a fairly short-history of progressive symptoms, which can be measured in days or weeks. It is strange for symptoms to present for more then a few months.

Diagnosis

Imaging features are nonspecific but useful in identifying potential AT/RT. In the posterior fossa, the tumors frequently invade the cerebellarpontine angle and may have areas of necrosis. Likewise, the supratentorial tumors are likely to be huge, insidious, and have necrotic mechanisms. The CT scan appearance is usually that of a hyperdense mass that improves intensely with distinction.

Treatment Options

AT/RT is a lethal disease, with initial retrospective studies showing a time-course from diagnosis to death of about 12-months with standard therapy. There are, still reports of long-term survivors. Various treatment options are available for atypical teratoid rhabdoid tumor depending upon the severity of the disease.

Surgery:

No potential data exist about the effect of surgical resection on treatment outcome. Data obtained from the AT/RT registry advocates that patients having a gross total resection have a longer median survival. 10 out of the 14 long-term survivors in the registry who had total surgical resection remained free from the disease 9.5–96 months from diagnosis.

Chemotherapy:

For young age patients with AT/RT, chemotherapy has been found to be the major form of post-surgical adjuvant therapy. A range of chemotherapeutic moves has been exploited and the majority patients have received multi-agent treatment.

An additional therapeutic move towards patients with AT/RT is based on the IRS-III Study. This approach employs radiation therapy, hydrocortisone, intrathecal methotrexate, cytarabine and systemic chemotherapy with several agents.

Radiation therapy

Radiation therapy appears to have a rapid impact on survival for AT/RT patients. However, it is not clear whether early radiation followed by chemotherapy is more effective or not.

Reference

(Web): Brain Tumor: Atypical Teratoid / Rhabdoid Tumor (ATRT) – https://www.stjude.org/stjude/v/index.jsp?vgnextoid=5efc061585f70110VgnVCM1000001e0215acRCRD&vgnextchannel=bc4fbfe82e118010VgnVCM1000000e2015acRCRD

(Web): Atypical teratoid/rhabdoid tumors of the central nervous system – https://pinotti.org/images/ATRT%20-%20Univ%20AL.pdf