Case Report: Sellar hemangioblastoma mimicking a pituitary macroadenoma: a diagnostic and surgical pitfall.

Background: Sellar hemangioblastoma (HBL), an exceedingly rare and hypervascular tumor, represents a critical diagnostic pitfall as it frequently mimics the radiological features of a common pituitary adenoma. This misidentification poses a substantial risk of unexpected and severe intraoperative hemorrhage, complicating surgical management. Case presentation: A 64-year-old female presented with intermittent dizziness. Magnetic resonance imaging revealed a large, avidly enhancing solid sellar mass with cystic changes, which was preoperatively diagnosed as a pituitary macroadenoma. However, an attempted endoscopic endonasal resection was complicated by profuse, difficult-to-control hemorrhage, resulting in only a subtotal resection. The definitive diagnosis, established by postoperative histopathology, was hemangioblastoma (WHO Grade I). A retrospective review of the imaging highlighted key features suggestive of HBL, including prominent vascular flow voids and avid early-phase arterial enhancement, which were initially overlooked due to diagnostic bias toward the more common pathology. Conclusions: This case underscores the critical importance of maintaining a high index of suspicion for HBL when evaluating any sellar mass, despite its rarity. Radiological "red flags" such as prominent flow voids and early arterial enhancement on dynamic imaging should prompt both clinicians and radiologists to include HBL in the differential diagnosis. Accurate preoperative identification is paramount for optimizing surgical strategy-including consideration of preoperative embolization and the surgical approach-to mitigate the risk of life-threatening hemorrhage. Furthermore, suspected sellar HBL should trigger an evaluation for Von Hippel-Lindau (VHL) disease, irrespective of symptoms, as confirming this diagnosis may completely reshape the treatment strategy.