Paediatric Central Nervous System Tumors and Cysts — WACS Viva & Clinical Scenarios (Paediatric Neurosurgery and Congenital Anomalies)

Exam-style paediatric central nervous system tumors and cysts viva scenarios with examiner probes and model answers for Neurosurgery candidates.

Scenarios covered

• SCENARIO 1: A 6-year-old child presents with a 6-week history of early morning vomiting, progressive gait ataxia, and bilateral papilloedema. Cranial MRI demonstrates a midline fourth ventricular mass enhancing heterogeneously, associated with severe triventricular hydrocephalus. Outline your systematic preoperative workup, surgical corridor, and the management of acute postoperative complications including posterior fossa syndrome.
• SCENARIO 2: A 4-year-old child is referred with progressive bitemporal visual field loss, polyuria, polydipsia, and growth deceleration. Cranial MRI reveals a suprasellar, partially calcified cystic-solid mass compressing the optic chiasm and elevating the floor of the third ventricle. Formulate the differential diagnosis, surgical strategies, and the detailed perioperative endocrine and electrolyte management protocol.
• SCENARIO 3: A 9-month-old infant presents with rapidly increasing head circumference, a bulging anterior fontanelle, and downward ocular deviation. Neuroimaging demonstrates an avidly enhancing, lobulated intraventricular mass within the trigone of the left lateral ventricle. Discuss the differential diagnosis, vascular supply, surgical approaches, and intraoperative blood volume management in this infant.
• SCENARIO 4: A 7-year-old child presenting with focal seizures is found on contrast MRI to have an incidental, well-circumscribed, non-enhancing CSF-intensity lesion in the left middle cranial fossa with remodeling of the overlying sphenoid wing. Detail the Galassi classification system, outline the criteria for operative intervention, and compare the advantages and limitations of endoscopic fenestration versus cystoperitoneal shunting.
• SCENARIO 5: Discuss the histopathological and molecular classification of paediatric medulloblastoma (WNT, SHH, Group 3, and Group 4). Explain the risk-stratification criteria governing adjuvant therapy and provide the neurobiological rationale for avoiding or delaying craniospinal irradiation in children under 3 years of age.