Outcomes and surgical nuances in management of giant pituitary adenomas: a review of 108 cases in the endoscopic era

Abstract

OBJECTIVE Giant (maximum diameter ≥ 4 cm) pituitary macroadenomas are complex tumors that require resection for decompression of optic nerves, relief of mass effect, and symptom improvement. Given the lack of surgical accessibility, the lateral extent of the lesions, and the invasion of the cavernous sinus, management presents a significant challenge. Transsphenoidal, transcranial, and combined approaches have been viable options for resection. The authors present their findings from a large series of patients to characterize giant pituitary adenomas, document outcomes, and outline surgical nuances in resection of these tumors. METHODS The authors reviewed 887 consecutive patients who underwent resection of pituitary adenomas at a single institution. From this group, 108 patients with giant pituitary adenomas who underwent resection between January 1, 2002, and December 31, 2020, were identified for inclusion in the study. The patient demographics, clinical presentation, tumor imaging characteristics, surgical approaches, and postoperative outcomes were analyzed using descriptive statistics. RESULTS The mean preoperative tumor diameter in this cohort was 4.6 ± 0.8 cm, with a mean volume of 25.9 ± 19.2 cm3. Ninety-seven patients underwent transsphenoidal approaches only, 3 underwent transcranial resection, and 8 patients underwent a combined approach. Gross-total resection was achieved in 42 patients. Tumor stability without a need for additional therapy was achieved in 77 patients, with 26 patients undergoing subsequent adjuvant radiotherapy. Among 100 patients with sufficient follow-up, 14 underwent adjuvant therapy—repeat operation and/or adjuvant radiation therapy—because of recurrence or tumor progression. Six patients with recurrence were observed without additional treatment. Overall, the morbidity associated with removal of these lesions was 11.1%; the most common morbidities were cerebrospinal fluid leak (5 patients, 4.6%) and hydrocephalus (4 patients, 3.7%). One death due to postoperative pituitary apoplexy of the residual tumor and malignant cerebral edema occurred in this cohort. CONCLUSIONS Giant pituitary tumors still represent a surgical challenge, with significant morbidity. Gross-total resection occurs in a minority of patients. Surgical goals for removal of giant pituitary tumors should include attempts at removal of most tumor tissue to minimize the risk of residual tumor apoplexy by tailoring the approach along the major axis of the tumor. Experience with both transsphenoidal and multiple transcranial techniques is necessary for minimizing complications and improving outcomes.