Clinical characteristics, management, and prognosis of pembrolizumab-induced hypophysitis: retrospective analysis based on case reports

BackgroundPembrolizumab-induced hypophysitis is a rare but clinically important immune-related adverse event. Its clinical features and long-term outcomes are not fully defined.

This study aimed to summarize the clinical characteristics, management, and prognosis of pembrolizumab-associated hypophysitis to support early recognition and appropriate treatment.MethodsPubMed, EMBASE, Web of Science, WanFang Data, and CNKI were searched for reports of pembrolizumab-induced hypophysitis published up to Jan 31, 2026, using relevant keywords and Boolean operators. Eligible case reports and case series were screened, and patient-level data were extracted using a standardized form.

Study quality was assessed with the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Reports.ResultsA total of 22 patients were included. The median age was 66 years (range 39–85), with equal distribution between males and females.

The median time to onset was 15 weeks (range 2–36), most frequently occurring within 11–20 weeks. Fatigue was the predominant symptom (86.4%), followed by nausea/vomiting (54.5%), adrenal insufficiency manifestations (40.9%), hyponatremia (31.8%), and headache (27.3%).

Median cortisol and ACTH levels were markedly reduced at 0.9 μg/dL and 5.0 pg/mL, respectively.