2025 Data (Information)

Prospective observational study of 118 clinically nonfunctioning pituitary adenomas: supplemental figure

Freda, Pamela U.

Purpose: A clinically nonfunctioning pituitary adenoma (CNFPA) is the likely diagnosis in a patient presenting with a sellar mass consistent with an adenoma on imaging and no clinical or lab evidence of hormone excess. A better understanding of the outcome of observation alone for CNFPAs not requiring surgery at diagnosis is needed.

Methods: We conducted a prospective, observational study of apparent CNFPAs ≥ 6mm in diameter following ES guidelines for clinical, endocrine and imaging follow-up.

Results: 118 patients aged 56 (range 24.7-81) yr., of which 62% were female and 72% macroadenomas, were followed for a median of 3.9 yr. (range 0.42-16 yr.). On follow-up, 49% increased (56% of macro- and 31% of microadenomas), 12% decreased and 39% were unchanged in size. The median time to increase in size was 2.2 (0.43-12.8) yr. for macro- and 3.44 (0.41-7.4) yr. for microadenomas (P =0.16). Twenty-nine (24.6%) patients (26 that were macro- and 3 that were microadenomas at diagnosis) underwent pituitary surgery after 2.58 (0.4-7.6) yr. of follow-up. Multivariable analysis found male sex to be a significant predictor of tumor growth and macroadenoma that of surgery. Most surgically removed CNFPAs were typical, hormone immuno-negative or gonadotropin staining tumors.

Conclusions: In this prospective study of 6-9 mm micro-CNFPAs and macro-CNFPAs followed conservatively, growth and surgery can occur within the first year or after many years of observation. Risks of enlargement and surgery are increased for some patient groups. These factors should be considered in designing a plan for follow-up.