Purpose: Transsphenoidal surgery for non-functioning pituitary adenomas (NFPAs) can alter pituitary function. We assessed the rates of improvement and deterioration of pituitary function by axis and searched for predictive factors of these outcomes.

Methods: We reviewed consecutive medical files from patients having had transsphenoidal surgery for NFPA between 2004 and 2018. Pituitary functions and MRI imaging were analyzed prior and after surgery. The occurrence of recovery and new deficit were documented per axis. Prognostic factors of hormonal recovery and new deficits were searched.

Results: Among 137 patients analyzed, median tumor size of the NFPA was 24.8 mm and 58.4% of patients presented visual impairment. Before surgery, 91 patients (67%) had at least one abnormal pituitary axis (hypogonadism: 62.4%; hypothyroidism: 41%, adrenal insufficiency: 30.8%, growth hormone deficiency: 29.9%; increased prolactin: 50.8%). Following surgery, the recovery rate of pituitary deficiency of one axis or more was 46% and the rate of new pituitary deficiency was 10%. Rates of LH-FSH, TSH, ACTH and GH deficiency recovery were 35.7%, 30.4%, 15.4%, and 45.5% respectively. Rates of new LH-FSH, TSH, ACTH and GH deficiencies were 8.3%, 1.6%, 9.2% and 5.1% respectively. Altogether, 24.6% of patients had a global pituitary function improvement and only 7% had pituitary function worsening after surgery. Male patients and patients with hyperprolactinemia upon diagnosis were more likely to experience pituitary function recovery. No prognostic factors for the risk of new deficiencies were identified.

Conclusion: In a real-life cohort of patients with NFPAs, recovery of hypopituitarism after surgery is more frequent than the occurrence of new deficiencies. Hence, hypopituitarism could be considered a relative indication for surgery in patients with NFPAs.