2026 Poster Presentations
P217: BIOCHEMICAL AND RADIOGRAPHIC OUTCOMES OF PROLACTIN-STAINING PITUITARY NEUROENDOCRINE TUMORS: OUTCOMES FOLLOWING ENDOSCOPIC ENDONASAL TRANSSPHENOIDAL RESECTION OF SILENT, CLINICALLY SILENT, AND FUNCTIONAL PITNETS
Thomas Hanks, BS; Jessica Eaton, MD; Chris Seward, MD; Tyler Lazaro, MD; Wenxuan Xiong, PhD; Eric Lassiter, BS; Rya Berrigan, BS; Jack Sedwick, BS; Rose Wang, BS; Kyle Montgomery, BS; Patrick Bi, BS, MS; Ivan Brown, BS; Ian Humphreys, DO; Al-Waleed Abuzeid, MD; Aria Jafari, MD; Brent Wisse, MD; Manuel Ferreira, MD, PhD; Samuel Emerson, MD, PhD; Jacob Ruzevick, MD; University of Washington
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<0.001). Median tumor volume at presentation was 1.13 (0.362 – 2.70) cm3 for silent, 2.51 (0.864 – 5.749) cm3 for clinically silent, and 0.933 (0.254 – 3.96) cm3 for functional PitNETs (p=0.052). Tumor extension into the suprasellar space was present in 27 (28.4%) silent tumors, 23 (24.2%) clinically silent tumors, 45 (47.4%) functioning tumors (p=0.054). Of the entire cohort, 241 (86.7%) patients underwent radiographic GTR of their tumor. Postoperative biochemical remission was achieved in 37/39(94.9%) clinically silent and 90/117(76.9%) functioning PitNETs. Dopamine agonist therapy was re-started in the immediate postoperative period in 1(2.6%) clinically silent and 21(17.9%) functioning PitNET patients, and of these, 11 (52.4%) functioning patients developed resistance to dopamine agonist therapy requiring additional multidisciplinary management. Biochemical recurrence after surgery alone occurred in 4 (4.3%) functioning PitNETs and no clinically silent tumors (p=0.14) (Figure 1).
Conclusion: Outcomes for patients with distinct clinical presentations of prolactin PitNETs appear unique. Surgical intervention for PRL PitNET is an effective treatment strategy and should be considered as first-line treatment by experienced, multidisciplinary skull base teams.