Radiological Growth Patterns of Prolactinomas and Nonfunctioning Adenomas

Area of Science:

• Neuroendocrinology
• Neurosurgery
• Oncology

Background:

• Pituitary macroadenomas are tumors >10 mm.
• Nonfunctioning adenomas and prolactinomas are common types.
• Tumor growth patterns can affect surrounding structures, including optic pathways.

Purpose of the Study:

• To compare the growth patterns of nonfunctioning pituitary macroadenomas and prolactinomas.
• To determine if growth patterns correlate with visual field defects.

Main Methods:

• Retrospective analysis of 70 patients (35 nonfunctioning adenomas, 35 prolactinomas) from a provincial registry.
• MRI analysis for tumor volume, height, and direction of growth (superior/inferior).
• Visual field testing at diagnosis; statistical comparison using t-tests, Mann-Whitney U, ANOVA, and chi-square tests.

Main Results:

• Tumor height and volume were similar between prolactinomas and nonfunctioning adenomas.
• Prolactinomas showed significantly more inferior growth (10.2 mm vs. 5.0 mm) and less superior growth (2.9 mm vs. 7.3 mm) compared to nonfunctioning adenomas.
• Inferior growth of prolactinomas was associated with a lower incidence of visual field abnormalities (11.4% vs. 57.1%).

Conclusions:

• Pituitary prolactinomas exhibit a distinct inferior growth pattern compared to nonfunctioning adenomas.
• This inferior growth trajectory in prolactinomas is linked to a reduced risk of vision impairment.