Background and objective: We performed an analysis of early factors influencing the outcome of Cushing's disease treated by transsphenoidal pituitary surgery.
Patients and method: Prospective study of 29 patients who underwent transsphenoidal pituitary surgery for Cushing's disease. The prognostic value of preoperative and operative variables, histological findings and serum cortisol (measured at 8:00 a.m. the day after surgery) were analyzed.
Results: Of the 29 patients included in this study, 26 achieved postoperative remission while in 3 patients treatment failed. Tumor was identified at histology in 92.3% patients in the remission group and in 33.3% in the failure group, this difference being significant (p = 0.03). Median postoperative cortisol levels were 95.8 nmol/l in the remission group and 676 nmol/l in the failure group, this difference being significant (p = 0.024). Serum cortisol of 600 nmol/l correctly classified the remission and failure groups with a sensitivity of 100% and a specificity of 96%.
Conclusions: In our experience, no identification of an adenoma at histology and an early postoperative cortisol level higher than 600 nmol/l after transsphenoidal pituitary surgery for Cushing's disease was associated with a high risk of failed treatment.