Clinical and Anatomic Features of Supraglandular Pituitary Adenomas

OBJECTIVE: Supraglandular pituitary adenoma (SGPA) is one of the extraordinary pituitary adenomas and shows different clinical and radiologic features. We retrospectively reviewed our cases of SGPAs to elucidate the radiologic, anatomic, and clinical features. METHODS: We identified 9 patients with pathologically proven SGPA and classified them into 2 groups radiologically: either glandular or stalk types. Magnetic resonance images were correlated with intraoperative anatomic differences between the groups. Clinical and endocrinologic characteristics and surgical outcomes were reviewed. RESULTS: The proportion of SGPAs was 1.2% of all pituitary adenomas surgically treated in our patient cohort. The glandular-type tumors (n = 7) had a thinned or defective diaphragma sellae. There was a clear plane between the tumor and pituitary stalk. For the stalk-type tumors (n = 2), the diaphragma sellae was intact and no clear border between the mass and stalk was found. Endocrinologic and immunohistochemical evaluation showed that 5 of 7 glandular-type tumors (71%) were functioning pituitary adenomas, whereas 2 stalk-type tumors were nonfunctioning. Eight of 9 patients underwent an endoscopic endonasal approach and tumor was totally removed in 7 (78%). CONCLUSIONS: SGPAs are rare and preoperative diagnosis is possible based on their distinct radiologic, clinical, and anatomic features. SGPAs can be divided into 2 groups according to the anatomic features. The origin of tumor, whether the superior surface of the gland or the pituitary stalk, determined the location, extent, and relationship with the diaphragma sellae. The surgical outcome via an endoscopic endonasal approach was favorable.