Treatment Strategies and Long-Term Outcomes in Silent Corticotroph Adenomas: A Single-Center Retrospective Study of 367 Cases

BACKGROUND AND OBJECTIVES: Silent corticotroph adenoma (SCA) is a high-risk pituitary neuroendocrine tumor (PitNET) which exhibits more aggressive behavior than other nonfunctioning PitNETs. Some SCAs are observed to recur after total resection (TR). We aim to discuss the long-term outcomes after endoscopic endonasal surgery for SCAs and explore optimal treatment after operation. METHODS: Clinical data and intraoperative videos from 367 SCAs who underwent endoscopic endonasal surgery were retrospectively collected. Patients were categorized into TR and subtotal resection (STR) groups according to 3-month postoperative MRIs. Based on close-up intraoperative observation of the relationship between tumor and pituitary gland, diaphragm, and medial wall cavernous sinus, patients in the TR group were further subdivided into gross total resection (GTR) and near total resection (NTR) groups. Patients in the STR group were subdivided as STR followed by observation (STR + ob) and STR followed by adjuvant stereotactic radiosurgery (SRS) (STR + SRS). Kaplan-Meier analysis was used to compare the event-free survival among these subgroups. RESULTS: Headache (27.5%) and vision loss (55.3%) were the most common presenting symptoms. Cavernous sinus (CS) invasion was confirmed intraoperatively in 167 (45.5%) patients. After operation, 175 (47.7%), 83 (22.6%), 32 (8.7%), and 77 (21%) patients were divided into GTR, NTR, STR + ob, and STR + SRS groups, respectively. The mean follow-up time was 40.9 ± 25.8 months. There were 0, 17 (20.5%), 9 (28.1%), and 4 (5.2%) patients noted to have PitNET recurrence or progression in GTR, NTR, STR + ob, and STR + SRS groups, respectively. Event-free survival distribution in the NTR group was similar to that in the STR + ob group ( P = .696), which was significantly lower than that in the STR + SRS group ( P = .008). Adrenocorticotropic hormone (ACTH)-negative SCAs have lower preoperative ACTH levels and were more likely to invade CS than ACTH-positive SCAs. CONCLUSION: CS invasion was commonly seen in SCAs, often precluding GTR. Radical surgery and close follow-up were proposed. Early postoperative adjuvant SRS for remnant tumor should be considered.