Pituitary adenoma consistency affects postoperative hormone function: a retrospective study

Background: Tumor consistency recently emerged as a key factor in surgical planning for pituitary adenomas, but its impact on postoperative endocrine function is still unclear. Our study aimed to evaluate the impact of tumor consistency on the development of postoperative pituitary deficiencies. Methods: Single-center, retrospective analysis of consecutive pituitary surgeries performed between January 2017 and January 2021 at Policlinico Umberto I in Rome. All patients underwent radiological and biochemical evaluations at baseline, and hormone assessments 3 and 6 months after pituitary surgery. Postoperative MRI studies were used to determine resection rates following surgery. Data on tumor consistency, macroscopic appearance, neurosurgical approach, and intraoperative complications were collected. Results: Fifty patients [24 women, mean age 57 ± 13 years, median tumor volume 4800 mm3 [95% CI 620-8828], were included. Greater tumor volume (χ2 = 14.621, p = 0.006) and male sex (χ2 = 12.178, p < 0.001) were associated with worse preoperative endocrine function. All patients underwent transsphenoidal adenomectomy. Fibrous consistency was observed in 10% of patients and was associated with a Ki-67 greater than 3% (χ2 = 8.154, p = 0.04), greater risk of developing postoperative hormone deficiencies (χ2 = 4.485, p = 0.05, OR = 8.571; 95% CI: 0.876-83.908), and lower resection rates (χ2 = 8.148, p = 0.004; OR 1.385, 95% CI; 1.040-1.844). Similarly, worse resection rates were observed in tumors with suprasellar extension (χ2 = 5.048, p = 0.02; OR = 6.000, 95% CI; 1.129-31.880) and CSI (χ2 = 4.000, p = 0.04; OR = 3.857, 95% CI; 0.997-14.916). Conclusions: Tumor consistency might provide useful information about postoperative pituitary function, likely due to its impact on surgical procedures. Further prospective studies with larger cohorts are needed to confirm our preliminary findings.