A Novel Association Between Pituitary Tumor Apoplexy and Influenza A

ABSTRACT Objective: Pituitary adenomas have a population prevalence of less than 0.1%. They can rarely present with serious complications, such as pituitary tumor apoplexy with symptoms of sudden severe headache, vision impairment, nausea, and vomiting. Methods: To date, there has been no proven underlying mechanism for the development of pituitary apoplexy. We report a novel association between pituitary tumor apoplexy and influenza A, indicating an inflammatory pathology underlying influenza infection contributing to hemorrhage. Results: Our patient is a 44-year-old female with past medical history of hypertension and diabetes mellitus type 2 who presented with a 2-day history of visual deficits, progressively worsening headache, and dizziness. She reported fever, chills, myalgia, and cough and tested positive for influenza A. Magnetic resonance imaging of the brain revealed a large suprasellar macroadenoma with internal hemorrhage. She underwent emergent transsphenoidal excision of pathology-proven pituitary adenoma with apoplexy. Signs of the syndrome of inappropriate antidiuretic hormone and diabetes insipidus were frequently checked postoperatively and were absent. She received a 5-day course of oseltamivir and was discharged on levothyroxine 75 μg per day and maintenance steroids with oral hydrocortisone. Conclusion: Our patient developed pituitary apoplexy while symptomatic with a laboratory-proven diagnosis of influenza A. Hemorrhage associated with influenza A has been described in multiple organs, making this case of pituitary apoplexy more than just a coincidental finding. We hypothesize that an underlying inflammatory pathology due to influenza A infection contributed to the development of pituitary apoplexy in our patient. We recommend vaccination against influenza A for healthy adults and at-risk populations based on the Centers for Disease Control guidelines. Abbreviations: MRI = magnetic resonance imaging