Predictive value of pituitary tumor morphology on outcomes and complications in endoscopic transsphenoidal surgery

PURPOSE: Endoscopic transsphenoidal surgery (ETSS) is an increasingly utilized approach for resection of pituitary tumors. Prior studies have evaluated preoperative tumor size, location, and extent as prognostic factors for surgical resection. There is little data on the relationship between preoperative pituitary tumor radiographic morphology and surgical outcomes. STUDY DESIGN: Retrospective longitudinal study. SETTING: Single tertiary care institution. SUBJECTS AND METHODS: Preoperative magnetic resonance imaging and computed tomography scans from patients undergoing ETSS for pituitary tumor resections from 2007 to 2017 were retrospectively evaluated. A neuroradiologist classified these pituitary tumors into six morphologic groups, each defined by volume, dimensions, extension, and shape. Surgical difficulty, rates of incomplete resection, and postoperative complications were then stratified in relation to the morphologic groups. RESULTS: Pituitary tumors from 131 patients were classified from preoperative imaging into six characteristic morphologies: (1) microtumor, (2) round, (3) transverse oblong, (4) superior‐inferior oblong, (5) bilobed, and (6) large lobulated. Tumors that were characterized with the large lobulated, bilobed, and transverse oblong morphologies correlated with higher rates of postoperative evidence of residual tumor (70%, 36%, and 47%, respectively, all P < 0.002). Likewise, large lobulated, bilobed, and transverse oblong morphologies were also associated with intraoperative cerebrospinal fluid leaks (70%, 31%, and 35%, respectively, all P < 0.05). CONCLUSIONS: We describe a novel descriptive system for the morphology of pituitary tumors that can be determined from preoperative imaging. Different tumor morphologic groups are associated with varying degrees of gross tumor resection, complications, and surgical difficulty. Utilizing pituitary tumor morphology may aid surgeons in planning the extent of resection, need for complex closure, and patient counseling.