Pituitary adenomas associated with hydrocephalus: clinical characteristics, risk stratification, and clinical management.

OBJECTIVE

To characterize pituitary adenomas (PAs) complicated by hydrocephalus, identify factors associated with hydrocephalus occurrence and cerebrospinal fluid (CSF) diversion requirement, and develop a practical management framework.

METHODS

We retrospectively reviewed consecutive patients with histopathologically confirmed PAs who underwent endoscopic endonasal surgery between January 2020 and June 2024. Hydrocephalus was defined radiologically by an Evans' index > 0.30. Forty-five hydrocephalus cases were propensity score-matched 1:3 to 135 non-hydrocephalus controls. A temporally separated hydrocephalus cohort treated between July 2024 and March 2025 served as a validation cohort. Predictors of CSF diversion requirement and postoperative rescue diversion were evaluated using multivariable and exploratory pooled Firth logistic regression models.

RESULTS

Among 2,069 included patients, 45 (2.2%) had preoperative hydrocephalus. Compared with matched controls, the hydrocephalus cohort had greater tumor burden, more frequent suprasellar extension, longer operative time, greater blood loss, and a lower gross-total resection rate. Within the hydrocephalus cohort, the posterior extension phenotype (PE-positive) was the strongest preoperative structural correlate of CSF diversion requirement (OR 5.15, 95% CI 1.12-23.68), with AUCs of 0.809 in the training cohort and 0.845 in the temporal validation cohort. In exploratory pooled analyses, both PE-positive (OR 28.25, 95% CI 1.33-599.59) and intraoperative blood loss ≥ 800 mL (OR 15.94, 95% CI 1.78-143.00) were independently associated with postoperative rescue diversion.

CONCLUSION

Pituitary adenoma-associated hydrocephalus reflects increased perioperative complexity. The posterior extension phenotype and substantial intraoperative hemorrhagic burden identify higher-risk patients. Most can be managed with direct endoscopic endonasal resection without routine preoperative diversion.