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Clinical presentation, diagnosis, and risk stratification of medulloblastoma

Scott L Pomeroy, MD, PhD
Section Editors
Jay S Loeffler, MD
Patrick Y Wen, MD
Amar Gajjar, MD
Deputy Editor
April F Eichler, MD, MPH


Medulloblastomas are the most common malignant brain tumor of childhood and occur exclusively in the cerebellum. The disease is rare after the fourth decade of life.

The epidemiology, clinical presentation, diagnosis, and risk stratification of medulloblastoma in children and adults will be discussed here. The histopathology, molecular pathogenesis, treatment, prognosis, and delayed complications in survivors are discussed separately. (See "Histopathology and molecular pathogenesis of medulloblastoma" and "Treatment and prognosis of medulloblastoma".)


Approximately 500 children are diagnosed with a medulloblastoma each year in the United States [1,2]. Medulloblastoma is the most common malignant brain tumor of childhood, accounting for approximately 20 percent of all primary tumors of the central nervous system among children less than 19 years of age. The peak incidence is between five and nine years of age. Approximately 70 percent of patients are diagnosed before the age of 20. There is a slight increase in incidence between the ages of 20 to 24 years, and the disease is rare after the fourth decade, consistent with its embryonal origin.

Approximately 2 to 5 percent of medulloblastomas occur in association with either the nevoid basal cell carcinoma syndrome (NBCCS), caused by germline mutations in the patched-1 (PTCH1) gene, or familial adenomatous polyposis (FAP), caused by inactivating mutations in the adenomatous polyposis coli (APC) gene. Mutations in these genes predispose to the development of medulloblastoma through defects in pathways important in the pathogenesis of both sporadic and inherited tumors. (See "Histopathology and molecular pathogenesis of medulloblastoma", section on 'Genetic predisposition'.)


Patients with medulloblastoma present with a combination of signs and symptoms of increased intracranial pressure and cerebellar dysfunction evolving over a period of weeks to a few months. Magnetic resonance imaging (MRI) typically demonstrates a midline or paramedian cerebellar mass that enhances after contrast administration, and approximately one third of patients will have evidence of tumor dissemination through the subarachnoid space either by imaging or cerebrospinal fluid (CSF) examination.

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Literature review current through: Nov 2017. | This topic last updated: Jun 18, 2017.
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  1. McNeil DE, Coté TR, Clegg L, Rorke LB. Incidence and trends in pediatric malignancies medulloblastoma/primitive neuroectodermal tumor: a SEER update. Surveillance Epidemiology and End Results. Med Pediatr Oncol 2002; 39:190.
  2. Smoll NR, Drummond KJ. The incidence of medulloblastomas and primitive neurectodermal tumours in adults and children. J Clin Neurosci 2012; 19:1541.
  3. Wolpert, SM, Barnes, PD. MRI in Pediatric Neuroradiology, Mosby, St. Louis 1992.
  4. Poretti A, Meoded A, Huisman TA. Neuroimaging of pediatric posterior fossa tumors including review of the literature. J Magn Reson Imaging 2012; 35:32.
  5. Bourgouin PM, Tampieri D, Grahovac SZ, et al. CT and MR imaging findings in adults with cerebellar medulloblastoma: comparison with findings in children. AJR Am J Roentgenol 1992; 159:609.
  6. Miralbell R, Bieri S, Huguenin P, et al. Prognostic value of cerebrospinal fluid cytology in pediatric medulloblastoma. Swiss Pediatric Oncology Group. Ann Oncol 1999; 10:239.
  7. Perek D, Perek-Polnik M, Drogosiewicz M, et al. Risk factors of recurrence in 157 MB/PNET patients treated in one institution. Childs Nerv Syst 1998; 14:582.
  8. Eran A, Ozturk A, Aygun N, Izbudak I. Medulloblastoma: atypical CT and MRI findings in children. Pediatr Radiol 2010; 40:1254.
  9. Koral K, Gargan L, Bowers DC, et al. Imaging characteristics of atypical teratoid-rhabdoid tumor in children compared with medulloblastoma. AJR Am J Roentgenol 2008; 190:809.
  10. Gimi B, Cederberg K, Derinkuyu B, et al. Utility of apparent diffusion coefficient ratios in distinguishing common pediatric cerebellar tumors. Acad Radiol 2012; 19:794.
  11. Rumboldt Z, Camacho DL, Lake D, et al. Apparent diffusion coefficients for differentiation of cerebellar tumors in children. AJNR Am J Neuroradiol 2006; 27:1362.
  12. Fouladi M, Gajjar A, Boyett JM, et al. Comparison of CSF cytology and spinal magnetic resonance imaging in the detection of leptomeningeal disease in pediatric medulloblastoma or primitive neuroectodermal tumor. J Clin Oncol 1999; 17:3234.
  13. Terterov S, Krieger MD, Bowen I, McComb JG. Evaluation of intracranial cerebrospinal fluid cytology in staging pediatric medulloblastomas, supratentorial primitive neuroectodermal tumors, and ependymomas. J Neurosurg Pediatr 2010; 6:131.
  14. Northcott PA, Korshunov A, Witt H, et al. Medulloblastoma comprises four distinct molecular variants. J Clin Oncol 2011; 29:1408.
  15. Rutkowski S, von Hoff K, Emser A, et al. Survival and prognostic factors of early childhood medulloblastoma: an international meta-analysis. J Clin Oncol 2010; 28:4961.
  16. Ellison DW, Kocak M, Dalton J, et al. Definition of disease-risk stratification groups in childhood medulloblastoma using combined clinical, pathologic, and molecular variables. J Clin Oncol 2011; 29:1400.
  17. Chang CH, Housepian EM, Herbert C Jr. An operative staging system and a megavoltage radiotherapeutic technic for cerebellar medulloblastomas. Radiology 1969; 93:1351.
  18. Zeltzer PM, Boyett JM, Finlay JL, et al. Metastasis stage, adjuvant treatment, and residual tumor are prognostic factors for medulloblastoma in children: conclusions from the Children's Cancer Group 921 randomized phase III study. J Clin Oncol 1999; 17:832.
  19. Jenkin D, Shabanah MA, Shail EA, et al. Prognostic factors for medulloblastoma. Int J Radiat Oncol Biol Phys 2000; 47:573.
  20. Mazloom A, Zangeneh AH, Paulino AC. Prognostic factors after extraneural metastasis of medulloblastoma. Int J Radiat Oncol Biol Phys 2010; 78:72.
  21. Tabori U, Sung L, Hukin J, et al. Medulloblastoma in the second decade of life: a specific group with respect to toxicity and management: a Canadian Pediatric Brain Tumor Consortium Study. Cancer 2005; 103:1874.
  22. Tabori U, Baskin B, Shago M, et al. Universal poor survival in children with medulloblastoma harboring somatic TP53 mutations. J Clin Oncol 2010; 28:1345.
  23. Korshunov A, Remke M, Werft W, et al. Adult and pediatric medulloblastomas are genetically distinct and require different algorithms for molecular risk stratification. J Clin Oncol 2010; 28:3054.
  24. Pfaff E, Remke M, Sturm D, et al. TP53 mutation is frequently associated with CTNNB1 mutation or MYCN amplification and is compatible with long-term survival in medulloblastoma. J Clin Oncol 2010; 28:5188.
  25. Cho YJ, Tsherniak A, Tamayo P, et al. Integrative genomic analysis of medulloblastoma identifies a molecular subgroup that drives poor clinical outcome. J Clin Oncol 2011; 29:1424.
  26. Shih DJ, Northcott PA, Remke M, et al. Cytogenetic prognostication within medulloblastoma subgroups. J Clin Oncol 2014; 32:886.