Non-functioning pituitary macroadenoma: surgical outcomes, tumor regrowth, and alterations in pituitary function-3-year experience from the Iranian Pituitary Tumor Registry

The aim of this study was to assess clinical features and therapeutic outcomes in patients with clinically non-functioning pituitary macroadenomas (NFPMAs).

This is a retrospective cohort study of NFPMA patients treated surgically and followed periodically between 2015 and 2017 in a tertiary care center in Iran. Descriptive analysis was performed applying appropriate tests. Binary logistic regression models were used to determine the predictive factors for subtotal tumor resection (STR) and hormonal recovery. Data were analyzed by Stata software.

A total of 71 patients with a mean age of 50.6 ± 1.4 years were studied. The mean diameter of the adenoma was 26.8 ± 1.1 mm. The most frequent symptoms were headache (85.75%), visual field defect (VFD) (78.3%), and hypogonadal symptoms (40.3%). Gross total resection (GTR) was achieved in 45.1%. Preoperative hypopituitarism was observed in 50.7% of patients. Recovery of at least one axis occurred in 36.1% of the patients suffering from hypopituitarism preoperatively, while new-onset postoperative hormonal deficiency appeared in 14.3% of patients. Multivariate analyses showing preoperative tumor size (OR = 38.2; P = 0.008) and cavernous sinus extension (OR = 13.4; P = 0.020) were predictors of STR. Moreover, hormonal recovery was observed not to be related to age, gender, tumor size, or the extent of tumor resection.

Tumor size and cavernous sinus extension are the main predictors for STR. Notably, recovery of the gonadal axis in a large proportion of patients supports the surgical resection of NFPAM in patients suffering from gonadal deficiency, even in the absence of VFD.