Object: Adrenocorticotropic hormone (ACTH)-secreting pituitary macroadenomas are an uncommon cause of Cushing's disease (CD) and, subsequently, Nelson's syndrome (NS). They have been associated with low postoperative remission rates. The outcome of modern surgical treatment is unclear and thus was assessed in a series of 43 patients, with the goal of improving therapeutic results in patients with ACTH-secreting macroadenomas.
Methods: Thirty-seven patients presented with CD and six with NS. They represented 15% of the patients surgically treated at the authors' institution for ACTH-secreting adenomas. The median patient age was 38 years (range 14-71 years), and the mean duration of follow up was 37 months (range 1-108 months). Remission occurred in 25 (67.6%) of 37 patients with CD, whereas the disease persisted in 12 (32.4%) of 37 patients. After an initial remission, three (12%) of 25 patients demonstrated signs and symptoms indicative of disease recurrence. Among patients with NS, only one (16.6%) displayed remission. Invasion of the dura mater by tumor was histologically demonstrated in 10 patients with CD and in two patients with NS.
Conclusions: Comprehensive management of CD caused by ACTH-secreting macroadenomas through the appropriate use of combination therapy, including surgery, radiotherapy, radiosurgery, and adrenalectomy, can lead to outcomes similar to those for microadenomas. Disease recurrence and persistence rates are higher, often because of the invasiveness associated with macroadenomas. Remission of NS-associated macroadenomas is difficult to achieve. Strategies for the characterization and treatment of invasive macroadenomas are needed.