Bless!
What is a rhabdoid tumor?
A rhabdoid tumor is a rare and highly malignant tumor of childhood, first
described in 1978. These tumors were initially considered an aggressive
variant of Wilms' tumor of the kidney, however, with newer diagnostic
techniques, these tumors are believed to represent a distinct entity. Since
that time, there have been fewer than 50 cases reported, although it is
likely that some cases previously identified as medulloblastoma or as
primitive neuroectodermal tumors (PNET) are in fact rhabdoid tumors. These
tumors occur in young children, mean age at diagnosis of 3.5 years, with a
range of 2 to 13 years. There are no reported cases in adults. Rhabdoid
tumors occur equally in males and females. The location can be
supratentorial, intraventicular, and infratentorial.
As you read further below, you will find general information about rhabdoid
tumors. If you would like to view summary information about brain tumors
first, see the overview on brain tumors.
What are the symptoms of a rhabdoid tumor?
The symptoms depend on the location of the tumor and the age of the child.
The following are the most common symptoms of a rhabdoid tumor, however each
child may experience symptoms differently. Common symptoms may include:
seizures - can be the only presenting sign for supratentorial lesions
hydrocephalus - enlargement of the skull and pressure on the brain
raised intracranial pressure - the tumor blocks the normal flow of
cerebrospinal fluid and the tumor causes increased production of fluid,
resulting in headaches, morning vomiting, lethargy, and disturbances in
walking
enlarged head size or fontanels (the soft "spot" that occurs before the
bones in the head become solid) in infants
Due to the aggressiveness of these tumors, the duration of symptoms before
coming to medical attention is relatively short.
The symptoms of a brain tumor may resemble other conditions or medical
problems. Always consult your child's physician for a diagnosis.
How are rhabdoid tumors classified?
Rhabdoid tumors are considered mesenchymal nonmeningothelial tumors within
the WHO classification. These tumors are distinct from rhabdomyosarcomas.
Immunohistochemical staining shows positivity for vimentin, cytokeratin, and
epithelial membrane antigen. Neural markers are variably present. A
characteristic cytogenetic abnormality has been identified, the deletion of
22q (22q11) which can aid in differentiating these tumors from other poorly
differentiated malignant brain tumors.
How is a rhabdoid tumor diagnosed?
Diagnostic procedures for rhabdoid tumor may include:
magnetic resonance imaging (MRI) - a diagnostic procedure that uses a
combination of large magnets, radiofrequencies, and a computer to produce
detailed images of organs and structures within the body. MRI provides
greater anatomical detail than CT scan and can better distinguish between
tumor, tumor-related swelling and normal tissue.
magnetic resonance spectroscopy (MRS) - a test done along with MRI at
specialized facilities that can detect the presence of particular organic
compounds produced by the body's metabolism within sample tissue that can
identify tissue as normal or tumor, and may be able to distinguish between
glial tumors and tumors of neuronal origin
What are the treatments for a rhabdoid tumor?
Specific treatment for a rhabdoid tumor will be determined by your child's
physician based on:
your child's age, overall health, and medical history
type, location, and size of the tumor
extent of the disease
your child's tolerance for specific medications, procedures, or therapies
how your child's doctors expect the disease to progress
your opinion or preference
A multidisciplinary approach, involving the neurosurgeon, pediatric
oncologist, neurologist, and radiation oncologist is needed for these
patients. Treatment may include (alone or in combination):
surgery - aggressive surgical removal followed by chemotherapy is standard
treatment
radiation therapy - children over 3 years of age will receive craniospinal
radiotherapy with a boost to the primary tumor. For children under 3,
radiotherapy is generally deferred, however, focal radiation therapy has
been incorporated into some treatment protocols designed for this age group.
Radiation therapy uses high-energy rays (radiation) from a specialized
machine to damage or kill cancer cells and shrink tumors.
chemotherapy - a drug treatment that works by interfering with the cancer
cell's ability to grow or reproduce. Different groups of chemotherapy drugs
work in different ways to fight cancer cells and shrink tumors. Often, a
combination of chemotherapy drugs is used to fight a specific cancer.
Certain chemotherapy drugs may be given in a specific order depending on the
type of cancer it is being used to treat.
While chemotherapy can be quite effective in treating certain cancers, the
agents do not differentiate normal healthy cells from cancer cells. Because
of this, there can be many adverse side effects during treatment. Being able
to anticipate these side effects can help the care team, parents, and child
prepare, and, in some cases, prevent these symptoms from occurring, if
possible.
Chemotherapy is systemic treatment, meaning it is introduced to the
bloodstream and travels throughout the body to kill cancer cells.
Chemotherapy can be given:
as a pill to swallow
as an injection into the muscle or fat tissue
intravenously (directly to the bloodstream; also called IV)
intrathecally - chemotherapy given directly into the spinal column with a
needle
Chemotherapy regimens have varied for patients with rhabdoid tumors,
although none has been considered curative. Protocols have used cis-platin,
VP-16, cyclophosphamide, and vincristine. Regimens for extracranial rhabdoid
tumors have employed ifosfamide, doxorubicin, vincristine, and
cyclophosphamide. The prognosis is very poor although objective responses
have been observed but the duration is 2 to 5 months from diagnosis.
Recurrent disease is managed symptomatically with consideration for
palliative surgery and/or radiotherapy.
What is the latest research on rhabdoid tumors?
Children's Hospital and Dana-Farber Cancer Institute are conducting numerous
research studies that will help clinicians better understand and treat
rhabdoid tumors. For more information on current research, see the Brain
Tumor Program.
