Natural history of conservatively managed nonfunctioning pituitary macroadenomas in the elderly: A study from the Swedish Pituitary Registry.

PURPOSE: To investigate adenoma progression, pituitary function, visual impairment, and need for later surgery in elderly patients with conservatively managed nonfunctioning pituitary macroadenomas (macro-NFPAs). METHODS: Patients ≥ 65 years in the Swedish Pituitary Registry diagnosed 1991-2023 with macro-NFPA and a decision for conservative management were included (n = 673, 38% females). Data at diagnosis and at 1- and 5-year follow-up, defined as assessments closest to 1 year (0.5-<2.5) and 5 years (2.5-<7.5), were retrieved. Surgery was recorded up to 7.5 years. Variables included adenoma size, pituitary function, visual impairment, and surgery. Patients were stratified into age groups 65-72, 73-80, and ≥ 81 years. RESULTS: At diagnosis, mean age was 76 years, females were older (p < 0.001). Mean adenoma diameter and volume were 20 mm and 3067 mm³. Visual field defects and reduced visual acuity were seen in 20% and 12%, with no sex differences. Males had more hormone deficiencies (45% vs. 33%, p < 0.01). Hormone deficiencies and visual impairments increased with age (p < 0.001). The oldest subgroup had the largest adenomas (p < 0.01), with females having larger tumours (p < 0.05) and males more deficiencies (p < 0.05). Adenoma size, hormone deficiencies, and visual impairments remained stable over time within each age group. 6.7% underwent surgery during follow-up. In regression analyses, later surgery was associated with visual field defects at diagnosis (p < 0.05) but not with adenoma size. CONCLUSION: Pituitary surgery was uncommon in conservatively managed elderly patients with macro-NFPAs. Baseline visual field defects, but not tumour size, were associated with subsequent surgery, supporting regular individualised follow-up in these patients.