Spindle cell oncocytoma: illustrative case

Background: Spindle cell oncocytoma (SCO) is a rare, nonadenomatous sellar tumor that often mimics pituitary adenomas both radiographically and clinically, making diagnosis and treatment difficult.

Observations: A 67-year-old male presented with fatigue and weakness, with MRI revealing an enhancing sellar mass with suprasellar extension and laboratory findings consistent with panhypopituitarism. He underwent endoscopic endonasal resection, which revealed a fibrous, highly vascular tumor adherent to surrounding tissue, consistent with SCO on final pathological analysis. Gross-total resection (GTR) was achieved, and the patient has been monitored regularly with no signs of recurrence at 9 months postoperatively.