[Surgical treatment for Cushing's disease with negative results in high dose dexamethasone suppression tests]

Objective: To analyze the indication and the outcome of trans-sphenoidal surgery (TSS) in Cushing's disease (CD) with negative high dose dexamethasone suppression tests (HDDST) results. Methods: Eighteen cases of ACTH-dependent Cushing's syndrome (CS) with negative HDDST results in the Department of Neurosurgery in Shanghai Ruijin Hospital from January 2015 to December 2017 were retrospectively reviewed. All patients underwent TSS. There were 5 males and 13 females, with an average age of (41±14) years. Results: All patients underwent bilateral inferior petrosal sinus sampling (BIPSS) before the surgery and got evidence of pituitary origin of ACTH secretion. They were thus indicated for TSS. Immediate post-operative remission was achieved in ratio 17/18. There were no recurrences within a flow-up of 1 to 3 years. Pituitary ACTH secreting adenomas were pathologically confirmed in 15 cases, including the one who did not achieve post-operative remission. Thus, all 18 patients with negative HDDST results can finally be confirmed as CD. Conclusions: HDDST alone is not sufficient to eliminate CD. For patients with ACTH-dependent CS with negative HDDST results, BIPSS should be further performed. The fact of post-operative remission and the pathological confirm of ACTH secreting pituitary adenoma may add final evidence to the diagnosis of CD.