Postoperative Hormonal Outcomes in Patients with Large and Giant Non-functioning Pituitary Adenomas

To study hormonal axis (HA) dysfunction pre-operatively and at three months after surgery in patients with large (>3 cms) (Hardy's grade C) and giant (>4 cms) nonfunctioning pituitary adenomas (NFPA).

One hundred thirty nine patients operated between 2006 and 2017, with 3 months post-operative hormonal evaluation, were included in this retrospective study. HA damage was categorized as 0 to 3 based on number of axes (thyrotroph, corticotroph and gonadotroph) that were affected. Risk factors studied for HA dysfunction before and after surgery included duration of symptoms, size of tumor, diabetes mellitus, hypertension and extent of resection.

Preoperatively 45 (32.3%) had no axis involvement, 34 (24.4%), 36 (25.8%) and 24 (17.2%) had one, two and three axes involvement respectively. Thyrotroph axis was affected in most patients. Tumor volume had significant correlation with preoperative pituitary dysfunction (P < 0.000). Post-operatively HA function remained same in 100 (72%), improved in only 7 (5%) and worsened in 32 (23%) of the patients. Of the 3 HA, corticotroph function worsened in most patients. None of the patients who had dysfunction in all three axes had improvement after surgery. No significant risk factors were associated with post-operative pituitary function outcomes. Persistent diabetes insipidus was noted in six (4.3%) patients.

Pre-operatively anterior pituitary dysfunction is noted in nearly two-thirds of patients with large and giant NFA. Tumor volume >15 cc had significant correlation with pre-operative panhypopituitarism. Post-operatively, pituitary function remains the same in nearly three quarters of the patients. No significant risk factors were found for post-operative hormonal outcomes.