Association between pituitary adenoma consistency, resection techniques, and patient outcomes: a single-institution experience.

Objective: The present study aimed to investigate the association between pituitary adenoma (PA) consistency and other measurable tumor characteristics, extent of resection (EOR), postoperative complications, and outcomes.

Methods: In total, 507 PA resections were intraoperatively assigned a consistency grade from 1 (cystic/hemorrhagic tumors) to 5 (calcified tumors) based on intraoperative tumor characteristics. Tumor consistency was analyzed in tertiles (grades 1 and 2, grade 3, and grades 4 and 5) to determine associations with tumor characteristics, EOR, recurrence, postoperative outcomes, and complications.

Results: The cohort in this study included primarily macroadenomas (93.3%) comprised mostly of nonfunctional PAs (NFPAs) (79.5%), with 77.1% showing suprasellar extension, 16.6% showing infrasellar invasion, and 46.4% showing cavernous sinus invasion (CSI). PA consistency grades were as follows: grade 1 or 2 (40.6%), grade 3 (39.3%), and grade 4 or 5 (20.1%). Compared with grade 1 or 2, higher-consistency PAs were more common in men (p = 0.001) and trended toward lower rates of gross-total resection (GTR) (67.6% vs 53.5%, p = 0.06). Higher PA consistency was predictive of any postoperative complication (OR 1.23, 95% CI 1.05-1.43; p = 0.009), specifically including transient diabetes insipidus (DI) (OR 1.45, 95% CI 1.12-1.85; p = 0.004) and cranial nerve (CN) paresis (OR 3.45, 95% CI 1.56-7.69; p = 0.002). Higher consistency was a strong predictor of CN palsy (OR 3.33, 95% CI 1.52-7.30; p = 0.004) for NFPAs. Higher-consistency PAs were more frequently adrenocorticotropic hormone-positive in both univariable (OR 1.33, 95% CI 1.11-1.60; p = 0.002) and multivariable (OR 1.38, 95% CI 1.11-1.69; p = 0.004) analyses. Higher consistency was associated with lower rates of GTR on stratification by CSI for Knosp grade 3 (p < 0.001) and grade 4 (p < 0.001) PAs, but not in low-grade (Knosp grades 1 and 2) PAs.

Conclusions: Tumor consistency is an important consideration for the resection strategy, particularly for PAs with CSI, and a predictor of intraoperative CSF leaks and perioperative complications and outcomes, including EOR, CN paresis, and transient DI.