Biochemical and Radiographic Outcomes of Prolactin-Staining Pituitary Neuroendocrine Tumors: Outcomes Following Endoscopic Endonasal Transsphenoidal Resection of Silent, Clinically Silent, and Functional PITNETS

Introduction: Prolactin-staining pituitary neuroendocrine tumors (PRL PitNET) may be sub-classified by clinical and biochemical presentation to include 1) silent (normal serum prolactin levels), 2) clinically silent (elevated serum prolactin without clinical symptoms of hyperprolactinemia), and 3) functional (hyperprolactinemia with symptoms attributable to hyperprolactinemia). Objective: To better understand factors contributing to radiographic and biochemical remission following endoscopic endonasal transsphenoidal surgery (ETSS) of functional subtypes of PRL PitNET. Methods: An IRB-approved, retrospective cohort study of patients undergoing endoscopic endonasal transsphenoidal surgery for histologically confirmed PRL PitNET via the endoscopic endonasal approach between 2011 and 2024 was performed. Demographic as well as clinical, radiographic, and perioperative data were obtained from the electronic medical record. Patients were subsequently stratified into 1) silent (normal serum prolactin levels), 2) clinically silent (elevated serum prolactin without clinical symptoms of hyperprolactinemia), and 3) functional (hyperprolactinemia with symptoms attributable to hyperprolactinemia) cohorts for analysis. Results: In total, 278 patients underwent surgical resection of a histologically confirmed PRL PitNET, of which 59.0% were female. There were 90 (32.4%) silent, 47(16.9%) clinically silent, and 141(50.7%) functional PitNETs. Mean age at presentation was 53.8 ± 16.9 years for silent, 50.0 ± 13.9 for clinically silent, and 43.6 ± 13.8 years for functioning PitNETs (p