Giant pituitary adenomas--an enigma revisited. Microsurgical treatment strategies and outcome in a series of 250 patients.
Giant pituitary adenomas (> 4 cm) are a surgical challenge. We present our experiences in surgical management of these tumors in a series of 250 patients. Two hundred and fifty patients with giant pituitary adenomas were managed surgically at our center over last 13 years. Majority (92%) of patients presented with visual deterioration. Non-functioning tumors were found in 136 patients (54.3%). Among functioning adenomas, 63 patients (25.4%) had prolactinomas and 45 patients (18%) had GH-secreting adenomas; while 3 patients each had LH and ACTH- secreting adenomas. The maximum tumor diameter varied from 4 to 10.5 cm, with mean diameter of 5.4 cm. The factors determining choice of operative approach and surgical outcomes in these tumors were analyzed. Overall, 273 surgical procedures were performed in 250 patients. Of these, 110 were transsphenoidal, while 163 were transcranial approaches. A single surgical procedure was performed in 227 patients (89.2%). 23 patients (9.2%) underwent re-exploration either because of postoperative apoplexy or residual tumor. Overall, near total (>90%) tumor excision could be achieved in 74%, with improved vision in 53% and good outcome in 75% patients. The mortality and morbidity were 4.4% and 14%, respectively. The main goal of surgical treatment of giant pituitary adenoma is maximum possible tumor extirpation with minimal side effects, which can be achieved by careful preoperative planning of operative approach, based on directions of tumor extensions and invasiveness. Maximal surgical removal of giant adenomas offers best chances to control tumor growth when followed with adjuvant medical and radiation therapies.