Approach to Giant Pituitary Adenomas

Giant pituitary adenomas (GPAs), defined as adenomas with a diameter in any direction of 40 mm or more, are challenging lesions due to their size, configuration, and invasive tendency. The intrinsic complexity of these tumours requires the use of different therapies in a combined or sequential way. A multimodal approach and a therapeutic strategy involving a multidisciplinary team of expert professionals form the basis of therapeutic success in these patients. Maximal surgical removal of giant adenomas through the transsphenoidal or transcranial approach, or both, aimed to relieve compression of the optic pathway and reduce tumour volume as much as possible, offers the best chances to control the tumour when followed with adjuvant medical and radiation therapies. Most enclosed adenomas even with large suprasellar extension, provided that the tumour extends symmetrically in the midline above the sella turcica are an indication for endonasal transsphenoidal approach and transcranial approach is indicated only for irregular multinodular shaped tumour, or eccentric extensions into the subfrontal, temporal, or retrosellar (posterior fossa) regions that cannot be reached through the transsphenoidal route. Irrespective of the surgical approach, massive intracranial extension, an irregular configuration, and marked cavernous sinus (CS) invasion are inherent factors that independently limit effective resection. These high-risk tumours require an individualized therapeutic strategy. To achieve radical resection of the GPA, one should determine if a single stage with one approach, either endonasal-transsphenoidal or through a craniotomy, could achieve that goal. In most of the irregularly shaped multicompartmental GPAs, this will not be possible. Therefore, one should think of the possibility to combine endonasal-transsphenoidal approach with a craniotomy, either in two separate stages, or combined in a single surgery.