A 56-year-old woman was found to have a large mass in her sinus cavity that had eroded bone and spread to the area around her pituitary gland, mimicking a pituitary tumor. Through surgery and pathological examination, doctors discovered it was actually a fungal infection (fungus ball) rather than a tumor. This case report reviews 67 similar patients from medical literature to help doctors better recognize and treat these rare fungal infections that can threaten vision and endocrine function.