Prediction Tumour Bed Bleeding Between MRI Features and Histopathological Findings in Atypical Pituitary Adenoma

Atypical pituitary adenomas (APAs) exhibit aggressive histological and radiological features. However, the occurrence of intra-operative tumour bed bleeding (TBB) during surgical management of pituitary adenoma remains unclear. This study aimed to investigate the correlation of TBB with MRI features and histopathological findings in APA. Pituitary adenomas of 194 patients were underwent surgical treatment in our neurosurgical centre from January 2012 to June 2014. 17 patients with final diagnosis of APAs were enrolled in the study. Clinical, radiological and histopathological data TBB volume, MRI features and immunochemical stains were assessed to predict the severity of intra-operative bleeding. The incidence of APAs was for 8.7% (17/194) found in our study. 14 patients exhibited minimal to moderate intra-operative TBB. 2 patients had severe TBB with blood loss more than 1000 mL. Total resection was achieved in 14 patients, and subtotal resection was achieved in 2 patients owing to severe bleeding or tumour involvement of the cavernous sinus. The most commonly MRI features of APAs included T1 iso-, T2 iso-hyperintensity with homogeneous enhancement after using a contrast medium. The mean MIB-1(Ki-67) positive of all atypical lesions was 7.4% ± 4.6%. The numbers of CD34+ cells are 26.8 ± 7.70 and 10.6 ± 5.34 in APAs and pituitary adenomas, significant difference between the two groups (t = 11.160, P < 0.05). Histopathological staining, MRI features and CD34+ overexpression in the APAs group are suggested massive intra-operative TBB. APAs is a very rare subtype of pituitary adenomas. High CD34+ expression and hypervascularity in MRI feature are indicative of severe TBB during surgery. Large randomised controlled trials are necessary to further evaluate the potential difference between APAs and their typical counterparts.