Endocrine Abstracts

Introduction: Surgery in nonfunctional pituitary adenomas (NFPAs) is usually indicated when there is mass effect or progressive increase in size. Our study aims to analyze NFPAs which were operated until the end of 2023 in a well-defined population.

Methods: A retrospective analysis of 128 operated patients with NPFAs, diagnosed at the only central national service hospital in Malta, between January 1980 and December 2023, was performed. Detailed clinical data was obtained for each patient and the pre- and post-operative MR pituitary scans were analysed. Univariate and multivariate analyses were done to establish which variables can predict the presence of residual and/or recurrence post-operatively.

Results: 72 (56.3%) were males and the median age was 56 years (IQR 42.5-64.5). The median tumour size was 27.6mm (IQR 21.5-35.1) with giant macroadenomas making up 10.2%. The median follow-up was 10.5 years (IQR 5-17). Most patients were operated once, 11 were operated twice, and only 2 thrice. During the study period 24 (18.8%) patients passed away. 103 patients (80.5%) had an accessible baseline MR pituitary, of which 95 (74.2%) tumours had chiasmal compression, 120 (93.8%) had suprasellar extension and 56 (43.8%) had cavernous sinus invasion. A residual post-operatively was detected in 80 (62.5%) patients. During follow-up, regrowth was detected in 25 (19.5%) patients with a median of 38 months from surgery (IQR 17-60). Univariate analysis revealed a statistically significant association between tumour residual and cavernous sinus invasion (P<0.001), largest tumour diameter (P<0.001), tumour volume (P<0.001), suprasellar extension (P=0.04) and infrasellar extension (P<0.001). The largest tumour diameter remained an independent predictor of having a residual post-operatively after logistic regression (P=0.008; OR 1.34 95% CI 1.08-1.68). Using ROC analysis to predict the presence of residual post-operatively, an infrasellar dimension of 5.2 mm was 80% sensitive and 70% specific (ROC-AUC 0.786, P<0.001). Tumour regrowth was statistically significantly associated with cavernous sinus invasion (P=0.002), tumour residual (P=0.003), largest tumour diameter (P=0.032) and transverse dimension (P<0.001). The transverse dimension remained an independent predictor of regrowth after logistic regression (P=0.005 OR 1.24 95% CI 1.07-1.44). There was no significant association between mortality and tumour residual or regrowth post-operatively.

Conclusion: The majority of operated NFPAs have good prognoses with few having significant regrowth despite residual tumours. An infrasellar dimension of 5.2mm was 80% sensitive and 70% specific to predict tumour residual post-operatively whilst the transverse dimension preoperatively was found to be independently associated with risk of regrowth.