Outcome of pituitary hormone deficits after surgical treatment of nonfunctioning pituitary macroadenomas.

Objectives: Nonfunctionning pituitary macroadenomas (NFPMA) are benign tumors that cause symptoms of mass effects including hypopituitarism. Their primary treatment is transsphenoidal surgery. We aimed to determine the outcome of pituitary hormone deficits after surgical treatment of NFPMA and to identify factors predicting hormonal recovery.

Design: We retrospectively included 246 patients with NFPMA diagnosed and operated in one of the two participating centers. All hormonal axes were evaluated except growth hormone (GH). Postoperative improvement of pituitary endocrine function was considered if at least one hormonal deficit had recovered and a lower total number of deficits was observed 1 year after surgery.

Results: 80% (n = 197) of patients had one or more pituitary deficits and 28% had complete anterior hypopituitarism. Besides GH, the gonadotropic and thyrotropic axes were the most commonly affected (68% and 62%, respectively). The number of hypopituitary patients dropped significantly to 61% at 1 year (p < 0.001) and a significant improvement was observed for all hormonal axes, except central diabetes insipidus. Among patients with preoperative hypopituitarism, 88/175 (50%) showed improved pituitary function at 1 year. Both hyperprolactinemia at diagnosis and a lower tumor diameter independently predicted favorable endocrine outcome.

Conclusions: Hypopituitarism is present in 80% of patients with NFPMA and nearly half of them will benefit from sustained improvement after surgery. Hyperprolactinaemia at diagnosis and lower tumor dimensions are associated with favorable endocrine prognosis. This supports the option of early surgery in NFPMA patients with pituitary deficits independent of the presence of visual disturbances.