Merck Manual

Please confirm that you are a health care professional

Loading

Medulloblastoma

By

Renee Gresh

, Nemours A.I. duPont Hospital for Children

Last full review/revision Jul 2019| Content last modified Jul 2019
Click here for Patient Education

Medulloblastomas are invasive and rapidly growing childhood central nervous system tumors that develop in the posterior fossa (containing the brain stem and cerebellum). Diagnosis is based on MRI and biopsy/tumor resection. Treatment is a combination of surgery, radiation therapy, and chemotherapy.

Medulloblastoma is the most common malignant posterior fossa tumor in children and the second most common of all pediatric central nervous system cancers (about 20% of the total). It has a bimodal peak at age 3 to 4 years and at age 8 to 10 years but can occur throughout childhood. Medulloblastoma is a type of primitive neuroectodermal tumor (PNET).

Etiology of medulloblastoma is unknown in most patients, but medulloblastoma may occur with certain syndromes (eg, Gorlin syndrome, Turcot syndrome).

Symptoms and Signs

Patients present most commonly with vomiting, headache, nausea, visual changes (eg, double vision), and unsteady walking or clumsiness.

Diagnosis

  • MRI

  • Histologic evaluation of biopsy specimen or entire resected tumor

MRI with gadolinium contrast is the test of choice for initial evaluation of possible medulloblastoma. Definitive diagnosis is made using tumor tissue obtained by biopsy or ideally by gross total resection of the tumor at initial presentation.

Once the initial diagnosis is established, staging and risk group determination are critical in medulloblastoma.

Staging tests include

  • MRI of the entire spine

  • Lumbar puncture for cerebrospinal fluid cytology

  • Postoperative MRI to assess for any residual tumor

Risk assessment is based on amount of residual tumor, and evidence of spread of disease:

  • High risk: Postoperative residual disease is > 1.5 cm2 or there is disseminated microscopic or gross disease.

  • Average risk: Postoperative residual disease is < 1.5 cm2 and there is no dissemination.

Prognosis

Prognosis depends on the stage, histology, and biologic (eg, histologic, cytogenetic, molecular) parameters of the tumor and patient age, but generally

  • Age > 3 years: Likelihood of 5-year disease-free survival is 50 to 60% if the tumor is high risk and 80% if the tumor is average risk.

  • Age 3 years: Prognosis is more problematic, in part because up to 40% of children have disseminated disease at diagnosis. Children who survive are at risk of severe long-term neurocognitive deficits (eg, in memory, verbal learning, and executive function).

Treatment

  • Surgery, radiation, and chemotherapy

Treatment of medulloblastoma includes surgery, radiation, and chemotherapy. Cure with chemotherapy alone has been shown in some children < 3 years of age. Autologous hematopoietic stem cell transplantation may also be used to treat certain patients. Combination therapy typically provides the best long-term survival.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Also of Interest

Videos

View All
Overview of Tetralogy of Fallot
Video
Overview of Tetralogy of Fallot
3D Models
View All
Cystic Fibrosis: Defective Chloride Transport
3D Model
Cystic Fibrosis: Defective Chloride Transport

SOCIAL MEDIA

TOP