A 5-year-old male presented with a 1 month history of headache and vomiting. Imaging showed a hyperintense solid mass in the fourth ventricle with surrounding edema and hydrocephalus. MRI revealed a heterogeneous mass in the posterior fossa filling the fourth ventricle and invading the vermis, with areas of necrosis and decreased diffusion. The mass strongly enhanced with contrast. Based on these findings, the diagnosis was medulloblastoma, a highly malignant pediatric brain tumor originating in the cerebellum.

1. Imaging Department
Feb 1 9 th
, 20 1 3
Reported by Dr. Giang

2.  Name: Nong Van Hieu
 Sex: Male
 Age: 5 years old.
 Dept: A13

3. Clinical
 Headache & vomiting for 1 month
 No fever
 No seizure
 Family’s history: older sister die when 10 years old
because of Epilepsy.

4. CT Findings
(From Ha Giang Hospital)
 Hyperintense solid mass in 4th
ventricle with edema surround
 Hydrocephalus
 NHP

5. MRI Findings
(T2WI, axial, Pre C+)
 Hyper-signal & Heterogenous mass in posterior fossa (43x40x49 mm)
 Fill up IV ventricle  Hydrocephalus
 Some necrosis areas
 Vermis invasion.

6. MRI Findings
(Flair , Coronal, Pre C+)
 Hyper-signal intensity.
 Spherical & well-defined

7. MRI Findings
(T1WI, Sagital, Pre C+)
 Hypointense to gray matter
 No hemorrhage intra mass

8. MRI Findings
(Diffusion & ADC)
 Diffusion: Decrease diffusion
 ADC : Hypo signal
 High density of cells

9. MRI Findings
(T1WI, Axial, Post C+)
 Strong enhancement
 Heterogenous (necrosis areas)

10. MRI Findings
(T1WI, Sagital, Post C+)
 Strong enhancement
 Heterogenous

11. MRI Findings
(T1WI, Coronal, Post C+)
 Strong enhancement
 Heterogenous

12. Diagnosis
Medulloblastoma

13. Background of MB
 Medulloblastoma: is a highly malignant primary brain tumor that originates
in the cerebellum or posterior fossa. ( PNET-MB)
 Epidemilogy: 15- 20% of all Pediatric brain tumor
30-40% of posterior fossa tumor in children
Rare in adult.
 Location: - 4th
ventricle, arises from roof.
- Cerebellar hemisphere : older children & adult.
 Age: 75% < 10 years. Most diagnosed by 5 year.
 Gender: M > F = 2-4 : 1
 Classification: 4 major PNET-MB subtype
- Classic
- Desmoplastic
- Extensive nodular with advanced neuronal differentiation
- Large cell

14. Background of MB
 Presentation: - Ataxia , signs of increased intracranial pressure.
(tumor rapid grow)
- Macrocephaly
- Cranial nerve palsies.
 Treatment:
 Surgical excision , adjyvant chemotherapy
 Craniospinal irradiation if > 3 years
 Top differential diagnosis:
 Ependymoma
 Atypical teratoid / rabdoid tumor

15. Thank you for attention!