Endocrine Abstracts

Introduction: The optimal management approach for incidental non-functioning pituitary microadenomas (micro-NFAs) is unclear. We aimed to capture current UK practice and identify changes following a 13-year interval.

Methods: Two surveys on micro-NFAs were conducted in 2009 and 2022 (advertised by Society for Endocrinology). Hormonal/imaging evaluations were explored.

Results: 2022: 150 clinicians participated. At baseline, ≥142 (95%) would measure prolactin, IGF-1, TSH/fT4, gonadal hormones and in 131 (87.9%), morning cortisol. 19 (12.8%) would check 24-hour UFC or ONDST. 67/142 (47.2%) would reassess pituitary function annually until discharge, 74/142 (52.1%) would only reassess if tumour growth/new symptoms of hypopituitarism. 23/149 (15.4%) would check visual fields in all. 6/148 (4.1%) would discharge after baseline imaging; 44 (31.0%), 26 (18.3%), 26 (18.3%) and 7 (4.9%) would discharge if MRI stable after 1, 2, 3 or 5 years, respectively. 10 (7.0%) would scan beyond 5 years and 20 (14.1%) at 1 and 2 years with life-long clinical follow-up. 2009: 214 clinicians participated; 204/213 (95.8%), 193/209 (92.3%), 155/204 (76.0%), 152/205 (74.1%), 124/198 (62.6%), 44/190 (23.2%) and 41/191 (21.5%) would measure prolactin, fT4, gonadotrophins, IGF-1, morning cortisol, 24-hour UFC, and LDDST, respectively. 47/190 (24.7%) would plot baseline visual fields. 197 (94.7%) would repeat MRI; 7 (3.6%), 68 (34.5%), 102 (51.8%), 19 (9.6%) and 1 (0.5%) would image after <6 months, 6-12 months, 1 year, >1 year, or non-specified interval, respectively. Responses on subsequent imaging strategies were highly variable. Compared to 2009, 2022 respondents were more likely to measure IGF-1 (96.0% vs 74.1%, P<0.0001) and morning cortisol (87.9% vs 62.6%, P< 0.0001), whilst less likely to dynamically assess adrenal reserve (11.4% vs 30.4% P<0.0001).

Conclusions: Biochemical evaluation of micro-NFAs has changed with time, now in concordance with current guidelines. Frequency of imaging surveillance remains variable, warranting generation of further evidence on the natural history of micro-NFAs.