Neuroimaging Assessment of Aggressive Pituitary Adenomas

Aggressive pituitary adenomas (APA) are adenomas that show rapid growth, invasiveness, frequent or multiple relapses, or are resistant to conventional therapies. Clinical-imaging assessment of aggressive pituitary adenomas with the aid of magnetic resonance imaging (MRI) plays an important role in early prediction, further disease outcomes and aggressive behavior of adenomas.

Purpose of the Study: was to assess the correlation of neuroimaging data with the hormonal activity of APA.

Materials and Methods: The study included 74 patients with aggressive pituitary adenomas. The average age of the patients was from 12 to 69. The patients underwent a basal assessment of the level of pituitary hormones: prolactin (PRL), GH (growth hormone), insulin-like growth factor-1 (IGF-1) and blood cortisol by the RIA method, as well as an MRI study. Knop's classification was used to assess the invasion.

Results: The hormonal workup showed prevalence of inactive pituitary adenomas among aggressive adenomas. No correlation was found between the hormonal activity of aggressive adenomas and the volume of pituitary adenomas. Moreover, MRI data indicated that invasion into the cavernous sinus of the III degree and heterogeneity of the adenoma may be considered equivalents of aggressiveness.

Conclusion: The established patterns support the need for visualization assessment of aggressive pituitary adenomas and strongly suggest the evaluation of the degree of aggression based on tumor heterogenecity, chiasm compression, hypo- and iso-intensity in T1 mode and hyperintensity in T2 modes.