Objective: Cushing’s disease (CD) comprises a spectrum of clinical manifestations secondary
to hypercortisolism due to ACTH-secreting pituitary adenoma. Transsphenoidal adenomectomy
remains the standard treatment with a recent surge in endoscopic approaches.
Methods: Data of all patients undergoing surgery for CD from 2009 to 2016 were analyzed retrospectively.
Postoperative cortisol level of < 2 μg/dL was taken as remission and value between
2 and 5 μg/dL as possible remission. Remission during follow-up was defined as morning
cortisol < 5.0 µg/dL or suppression of serum cortisol (<2 µg/dL) after overnight dexamethasone
test.
Results: A total of 123 patients of CD were included for analysis and were divided into two
groups; group A comprising 98 patients who underwent primary pituitary surgery and
group B of 25 patients who underwent pituitary surgery for nonremission. In group
A, 47 (47.9%) patients underwent microscopic surgery, 49 (50%) endoscopic surgery
and two (2%) were operated transcranially; in group B, the numbers are 15 (60%), 8
(13.3%), and 2 (3.3%), respectively. Remission was achieved in 75.9% patients in group
A and in 53.3% patients in group B. In statistical analysis, factors significantly
associated with remission were type of surgery (p = 0.01), postoperative day 1 morning cortisol (p = 0.004 and postoperative day 1 morning ACTH (p = 0.015). The chance of remission was significantly more with endoscopic approach
(40/45 = 88.9%) than microscopic (59.3%) or transcranial surgery (0/1 = 0%). ROC curve
showed a cut-off value of 10.5 µg/dL (p < 0.001 with 87% sensitivity and 80% specificity). The chance of intraoperative CSF
leak increased with macroadenoma (p = 0.07) and in redo surgery (p = 0.03).
Conclusion: Postoperative plasma cortisol level is a strong independent predictor of remission
and value less than 10.5 µg/dL can be taken as cut-off for predicting remission, though
it does not positively predict long-term recurrence. So, all patients with CD cured
by surgery require long-term follow-up. Endoscopic TSS has taken over microscopic
approach in the recent past and remission provided by endoscopy appears to be significantly
better than microscopic approach.
