Open Access

Mirko Hladik, Isabella Nasi-Kordhishti, Jens Schittenhelm, Benjamin Bender, Marcos Tatagiba, Jürgen Honegger, Felix Behling

• Background: Most pituitary adenomas are benign in nature and can be treated effectively by microsurgical resection, medical treatment and/or radiotherapy. However, invasive growth can be an important feature of a more aggressive behavior and adverse prognosis. Extension of pituitary adenomas into the cavernous sinus can be categorized according to the Knosp criteria on magnetic resonance imaging (MRI). The prognostic significance of intraoperatively detected invasive growth is unclear and comparative analyses of MRI features and intraoperative findings are still scarce. Methods: We performed a retrospective analysis of 764 pituitary adenomas that were surgically treated between October 2004 and April 2018. Invasive growth was assessed according to the surgical reports and preoperative MR-imaging (Knosp criteria). Clinical data such as age at diagnosis, patient gender, histopathological subtype as well as recurrence-free survival on follow-up imaging, were collected. Results: InvasiveBackground: Most pituitary adenomas are benign in nature and can be treated effectively by microsurgical resection, medical treatment and/or radiotherapy. However, invasive growth can be an important feature of a more aggressive behavior and adverse prognosis. Extension of pituitary adenomas into the cavernous sinus can be categorized according to the Knosp criteria on magnetic resonance imaging (MRI). The prognostic significance of intraoperatively detected invasive growth is unclear and comparative analyses of MRI features and intraoperative findings are still scarce. Methods: We performed a retrospective analysis of 764 pituitary adenomas that were surgically treated between October 2004 and April 2018. Invasive growth was assessed according to the surgical reports and preoperative MR-imaging (Knosp criteria). Clinical data such as age at diagnosis, patient gender, histopathological subtype as well as recurrence-free survival on follow-up imaging, were collected. Results: Invasive growth (Knosp grade 3A – 4) was seen in 24.35% (186/764) of the cases and based on intraoperative assessment in 42.41% (324/764). Overall, 19.07% of pituitary adenomas showed a recurrence. Invasion by intraoperative assessment was associated with older age (p=0.0374), male gender (p=0.0390), sparsely granulated corticotroph adenomas (p=0.0433), null cell adenomas (p=0.0368) and a shorter recurrence-free survival (p=0.0493) in the univariate analysis. Radiographic invasion was correlated with age (p=0.0018), sparsely granulated corticotroph adenomas (p=0.0264), null cell adenomas (p=0.0275) and a shorter recurrence-free survival (p=0.0008). Only radiographic invasion was an independent prognostic factor in the multivariate analysis. (p=0.0134). Conclusions: Only MRI invasion but not intraoperative evidence of invasion is an independent prognostic factor for inferior recurrence-free survival. MRI invasion as assessed by Knosp criteria can be used for prognostic evaluation and clinical decision-making.…