Histopathological and radiological predictors of surgical remission failure in GH-secreting pituitary adenomas

To evaluate the role of T2 signal intensity in differentiating granulation patterns in GH-secreting pituitary adenomas and identify key radiological and histological predictors of surgical remission failure.  METHODS : 107 GH-secreting pituitary adenomas were assessed for granulation patterns (DG, SG), tumor volume, normalized T2 signal intensity, extrasellar extension, and proliferative status. Patients were divided into two groups according to surgical remission status assessed at 6 months post-surgery.  RESULTS: 52 pituitary adenomas were DG and 55 were SG, with T2 signal intensity distinguishing the two subtypes. Infrasellar extension was more common than suprasellar or parasellar extension in both subtypes, with no significant difference in surgical remission rates between SG and DG tumors (p = 0.098).Surgical-remission and non-remission groups differed in tumor volume (p = 0.018), vertical infrasellar extension (p = 0.002), and cavernous sinus invasiveness (p = 0.009). Tumors in non-surgical remission group had larger volumes (2043.33 mm³ vs. 1647.60 mm³), greater infrasellar extension (5mm vs. 2.75mm), and higher cavernous sinus invasiveness (47.3% vs. 32.1%). Infrasellar extension and cavernous sinus invasiveness were predictive of surgical remission failure (OR, 1.186; p = 0.005; OR, 2.997; p = 0.023); an infrasellar growth cutoff greater than 4.93 mm was identified as a potential radiological marker for surgical remission failure (58% sensitivity, 71% specificity, AUC = 0.67, p < 0.001).  CONCLUSION: T2 signal intensity helps identify granulation patterns, but it does not predict surgical remission. Surgical remission failure is associated with cavernous sinus invasion and infrasellar extension greater than 4.93 mm, indicating more aggressive GH-secreting pituitary adenomas.