Pituitary adenoma and intracerebral aneurysms: case series, systematic review and meta-analysis

Purpose Intracranial aneurysms (IAs) and Pituitary Adenoma (PA) coexistence has been reported for decades, yet available evidence remains fragmented. We performed a systematic review and meta-analysis following PRISMA 2020 guidelines to assess clinical features of patients with both conditions and quantify the prevalence of IAs in PA patients. Methods PubMed and Embase were searched up to December 15, 2025. Studies reporting coexistence of IAs and PAs were included. Individual patient-level data (Group 1) and aggregate prevalence data (Group 2) were analyzed separately. Risk of bias (RoB) was assessed using Joanna Briggs Institute tools. All analyses were performed using metaprop function from the meta package in R software. Results Seventy-one studies met inclusion criteria. Most studies have a low RoB. In Group 1 (74 patients), PAs were predominantly macroadenomas (91.9%), most frequently non-functioning (40.5%). IAs were mainly in the cavernous segment of the internal carotid artery (33%). IA diagnosis occurred significantly later than PA diagnosis ( p < 0.01). In Group 2 (5264 patients), the pooled prevalence of IAs among PAs was 4% (95% CI 2–4%; I² = 92.1%, τ² = 1.1050, p < 0.0001). Sex-stratified prevalence was 8% (95% CI: 6%-9%) in females and 6% (95% CI: 4%–7%) in males. IAs sex-specific prevalence was significantly higher in both male and female PA patients as compared to the general population ( p < 0.01). Conclusion Patients with PAs show a higher IAs prevalence compared with the general population, likely reflecting combined hemodynamic, anatomical, and endocrine influences.