Intrasellar pressure–venous outflow imbalance in acute deteriorating giant pituitary adenoma

• Acute deterioration in giant pituitary adenomas may reflect an intrasellar compartment mechanism. • Venous outflow failure may drive edema-dominant expansion with petechial hemorrhage/HT. • Rapid interval growth plus sphenoid sinus roof mucosal thickening on MRI/CT should raise vigilance. • A clinic-oriented decision-cue framework supports short-interval reassessment and multidisciplinary discussion. • These cues may prompt discussion of timely decompression and stress-dose glucocorticoids when indicated.