Differential Diagnosis for a 7-year-old boy with lethargy, nausea, vomiting, papilledema, right-sided dysmetria, and a cerebellar cystic mass on MRI
- Single most likely diagnosis:
- Pilocytic Astrocytoma: This is a common benign brain tumor in children, often presenting with symptoms of increased intracranial pressure (such as lethargy, nausea, vomiting, and papilledema) and cerebellar signs (like dysmetria) due to its typical location in the cerebellum. The cystic appearance on MRI is also consistent with this diagnosis.
- Other Likely diagnoses:
- Medulloblastoma: Although more solid in appearance, medulloblastomas can have cystic components and are a common malignant brain tumor in children, often arising in the cerebellum. They can cause similar symptoms due to increased intracranial pressure and local cerebellar dysfunction.
- Hemangioblastoma: These are less common in children but can be cystic and are typically found in the cerebellum. They might present with similar symptoms, especially if they cause an obstruction of cerebrospinal fluid pathways.
- Do Not Miss diagnoses:
- Brain Abscess: Although less likely given the cystic mass appearance, a brain abscess can present with increased intracranial pressure symptoms and focal neurological signs. It is a medical emergency requiring prompt antibiotic treatment and possibly surgical drainage.
- Cerebellar Infarction or Hemorrhage: Acute cerebellar stroke can present with sudden onset of symptoms similar to those described, including increased intracranial pressure and cerebellar signs. It's crucial to identify and manage promptly to prevent further brainstem compression and hydrocephalus.
- Rare diagnoses:
- Ganglioglioma: A rare, usually benign tumor that can occur in the cerebellum and present with a mix of cystic and solid components on imaging. Symptoms would depend on the tumor's location and size.
- Dysplastic Cerebellar Gangliocytoma (Lhermitte-Duclos Disease): A rare, slow-growing tumor of the cerebellum that can cause increased intracranial pressure and cerebellar signs. It often has a characteristic appearance on MRI but is much less common than other cerebellar tumors in children.