Biomarkers of pituitary macroadenomas aggressive behaviour: a conventional MRI and DWI 3T study.

Pituitary macroadenomas (PAs) are usually defined as benign intracranial tumors. However, they may present local aggressive course. High Ki67 labelling index (LI) values have been related to an aggressive tumor behavior. A recent clinicopathological classification of PA based on local invasiveness and proliferation indexes, divided them in groups with different prognosis. We evaluated the utility of conventional MRI (cMRI) and diffusion-weighted imaging (DWI), in predicting the Ki67- LI according the clinicopathological classification. 17 patients (12 M and 5 F) who underwent surgical removal of a PA were studied. cMRI features, quantification of Negative correlations were observed between Ki-67 LI, ADCm (ρ = - 0.67, Adding quantitative measures of ADC values to cMRI could be used routinely as a non-invasive marker of specific predictive biomarker of the proliferative activity of PA. Routinely use of DWI on diagnostic work-up of pituitary adenomas may help in establish the likely biological aggressive lesions.