Sellar and Parasellar Lesions — WACS Viva & Clinical Scenarios (Neuro-Oncology and Skull Base Disorders)

Exam-style sellar and parasellar lesions viva scenarios with examiner probes and model answers for Neurosurgery candidates.

Scenarios covered

• SCENARIO 1: A 42-year-old female presents with a six-month history of progressive visual deterioration, bitemporal visual field restriction, oligomenorrhea, and galactorrhea. Contrast-enhanced sellar magnetic resonance imaging reveals a 2.6 cm macroadenoma expanding the sella turcica with suprasellar extension abutting the optic chiasm. Initial serum prolactin is markedly elevated at 3,500 ng/mL. Detail the complete diagnostic evaluation, the primary therapeutic strategy, indications for surgical intervention, and monitoring protocols.
• SCENARIO 2: A 56-year-old male with an untreated sellar mass presents to the emergency surgical unit with sudden severe retro-orbital headache, acute bilateral visual acuity collapse, diplopia, hypotension (blood pressure 80/50 mmHg), and altered mental status. Outline the acute stabilization, diagnostic confirmation, indications and timing for emergent transsphenoidal surgical decompression, and perioperative steroid therapy.
• SCENARIO 3: Describe the surgical anatomy, essential osseous and neurovascular landmarks, step-by-step operative technique, and closure protocol for an endoscopic endonasal transsphenoidal resection of a functional corticotroph adenoma in a patient with Cushing disease. Detail the intraoperative strategies to avoid injury to the cavernous internal carotid artery and methods for skull base reconstruction to prevent postoperative cerebrospinal fluid fistula.
• SCENARIO 4: An 8-year-old child presents with progressive headache, growth deceleration, bitemporal hemianopsia, and polyuria. Neuroimaging reveals a heterogeneous, predominantly suprasellar lesion with cystic components containing cholesterol-rich fluid and peripheral rim calcification, compressing the optic chiasm and elevating the floor of the third ventricle. Discuss the differential diagnosis, definitive surgical approaches (endonasal versus transcranial), and long-term neuroendocrine management.
• SCENARIO 5: A 48-year-old male undergoes gross total resection of a non-functioning pituitary macroadenoma via an uncomplicated endoscopic transsphenoidal approach. On postoperative day 2, his urine output increases to 450 mL/hour with a urine specific gravity of 1.003 and serum sodium of 149 mmol/L. Outline the diagnostic criteria, physiological mechanism, dynamic triphasic water balance pattern, and precise management protocols for postoperative diabetes insipidus, syndrome of inappropriate antidiuretic hormone secretion, and cerebral salt wasting.