Giant Pituitary Adenomas: Advantages and Limitations of Endoscopic Endonasal Surgery

Objective: Giant pituitary adenomas (exceeding 4 cm) represent an extreme surgical challenge. Endoscopic endonasal surgery (EES) has recently been used in their treatment.

Design: We present the results of EES and analyze the advantages and limitations of this technique.

Methods: We retrospectively reviewed the medical files and imaging studies of 54 patients with giant pituitary adenomas who underwent EES and studied the factors affecting the surgical outcome.

Results: Preoperative visual impairment was present in 45 patients (83%), partial or complete pituitary deficiency in 28 cases (52%), and 7 patients (13%) presented with apoplexy. Tumor resection greater than 85% was achieved in 45 patients (83.3%). Vision was improved or even normalized in 36 cases (80%) and worsened in 2 (4.4%). Significant factors that limited the degree of resection were multilobular configuration of the adenoma (P = 0.002) and middle fossa extension (P = 0.045). Cavernous sinus invasion, size, and intraventricular or posterior fossa extension did not influence surgical outcome. Complications included apoplexy of residual adenoma (3.7%), permanent diabetes insipidus (9.6%), transient cranial nerve palsies (11%), new pituitary insufficiency (16.7%), and cerebrospinal fluid leak (16.7%). After EES, 14 patients underwent radiotherapy for residual mass and 5 with functional pituitary adenomas received medical treatment. During a mean follow-up of 29.3 months (range, 1–109 months) seven patients were reoperated on for tumor recurrence.

Conclusions: EES provides effective initial management of giant pituitary adenomas with fewer limitations compared with transsphenoidal and transcranial approaches, advancing the frontiers of skull base surgery.