Endocrine Abstracts

Transsphenoidal surgery (TSS) is the most common first-line treatment for Cushing's disease (CD). We have examined the outcome of this intervention to identify pre-operative clinical factors that predict good surgical outcome and to determine the risk of adverse events.

We performed a case-notes review of 30 consecutive patients, 20 (67%) female, treated by a single surgeon over a 14-year period. The mean (SE) age was 34.2 (2.1) years and median (range) follow-up was 2.5 (0.5-14) years. Following TSS, 19 (63%) patients entered prolonged remission, 9 (30%) had persistent CD and 2 (7%) developed Nelson's syndrome. 4 patients with persistent CD and 1 patient with Nelson's entered remission following further treatment, giving a final remission rate of 80%. Positive radiology predicted good outcome; 14/16 (88%) patients with a definite microadenoma entered remission vs 5/12 (42%) with an equivocal or normal scan (p=0.02). Both patients with a macroadenoma had persistent CD. 4/9 (44%) patients with basal ACTH<50 nanograms/litre entered remission vs 6/9 (67%) patients with ACTH 51-100 nanograms/litre, and 6/7 (86%) with ACTH>100 nanograms/litre. 11/15 (73%) patients with unequivocal dynamic endocrine testing entered remission vs 8/15 (53%) with equivocal testing. There was no surgery-related mortality, but 8 (27%) patients had a CSF leak and 3 (10%) of these developed meningitis. 15 (50%) patients developed diabetes insipidus, in 8 (27%) this persisted. 9/19 (47%) patients in remission were panhypopituitary, 7/19 (37%) required long-term hydrocortisone and 2/19 (10%) were eupituitary. In addition, 8/11 (73%) patients with persistent disease were panhypopituitary.

In conclusion, remission rates for CD from this unit are comparable to other published series. Taken together, unequivocal dynamic endocrine testing and a positive MRI scan predict remission following TSS (8/8). Patients who meet neither criteria require further assessment before proceeding to TSS, as only 11/20 (55%) enter remission (p=0.03) and the risk of panhypopituitarism is high.