SOX 2 Expression in Human Pituitary Adenomas-Correlations With Pituitary Function

Background/Aim: The aim of this study was to evaluate SOX2 expression in pituitary adenomas and its correlation to their secretory state and clinicopathological parameters. Patients and Methods: Thirty-four patients were clinically evaluated and surgery was recommended for tumor removal. Histopathological diagnosis by hematoxylin eosin staining was followed by immunohistochemistry for pituitary hormones and SOX2 co-expression. Results: Fourteen of the 34 cases were GH-secreting adenomas, 10 were prolactinomas and 10 non-functioning pituitary adenomas. SOX2-positive expression was detected in 47.05% of total cases: 8 GH-secreting adenomas (57.14%), 6 prolactinomas (60%) and 2 non-functioning adenomas (20%). SOX2 positivity was significantly higher amongst secreting adenomas (p=0.041). SOX2-negative tumors were significantly associated with corticotrophin deficiency (p=0.047) and gonadotrophin deficiency (p=0.041). No correlation with tumor size or extrasellar extension was detected. Conclusion: SOX2 is differentially expressed in pituitary adenomas and influences the secretory state or clinical behavior of pituitary adenomas.