This study retrospectively identified 10 males and 14 females aged from 37 to 75 years (mean 56.8 years) with pituitary adenomas coexisting with intracranial aneurysms among the 923 patients (2.6%) initially treated by surgery with histological confirmation at the Department of Neurosurgery, Kohnan Hospital between April 2005 and October 2018. No patients had previously undergone treatment for the aneurysms and all aneurysms were un-ruptured. All patients were investigated preoperatively and just after the operation with coronal and sagittal T1-weighted, with and without contrast medium, and T2-weighted magnetic resonance (MR) imaging, and MR angiography with the time of flight method (1.5 T system, Magnetom, Siemens, Erlangen, Germany and Signa Horizon, General Electric Medical Systems, Milwaukee, WI; 3.0 T system, Signa Excite HD 3T, General Electric Medical Systems). Therapeutic strategies were established through discussions between neurosurgeons and endovascular neurosurgeons specialized in cerebrovascular diseases to decide the therapeutic priority and method of treatment of the cerebral aneurysms for each individual case.
The surgical specimens were immediately fixed for histological and immunohistochemical examinations with 10% buffered formalin, embedded in paraffin, and serial sections were cut to 3 µm thickness. Hematoxylin and eosin, and periodic acid-Schiff staining were performed in all cases. The avidin-biotin-peroxidase complex method was applied for immunohistochemical staining using the following antibodies: polyclonal anti-growth hormone (GH) (GH, Dako, Glostrup, Denmark), polyclonal anti-adrenocorticotropic hormone (ACTH) (ACTH, Dako), polyclonal anti-prolactin (PRL) (PRL, Dako), monoclonal anti-thyroid-stimulating hormone (SPM104, Lab Vision, Fremont, CA, 1:100), monoclonal anti-luteinizing hormone (LH) (LH01, Lab Vision, 1:500), monoclonal anti-follicle-stimulating hormone (FSH) (FSH03, Lab Vision, 1:500), and polyclonal anti-alpha-subunit hormone (CELL MARQUE, Rocklin, CA). Cell proliferation was assessed by immunohistochemical staining for Ki-67 (MIB-1, Dako, 1:100). If enough material was available, additional immunohistochemical staining was performed for mouse monoclonal anti-matrix metalloproteinase-9 (MMP-9) (15w2, Leica, Novocastra, UK, 1:80), goat polyclonal anti-hypoxia-inducible factor-1α (L2208, Santa Cruz Biotechnology, Inc., Santa Cruz, CA; 1:100), mouse monoclonal anti-vascular endothelial growth factor (VEGF) (JH121, Neo Markers, CA, 1:100), and mouse monoclonal anti-human cluster of differentiation 68 (CD68) (PGM1, Agilent, Dako, 1:200) as vascular remodeling factors.
Patients were subdivided into two groups with/without direct attachment of cerebral aneurysms to pituitary adenomas, and the immunohistochemical results were compared with the control group consisting of 21 pituitary adenoma patients without cerebral aneurysms. Statistical comparisons used Statmate 5 software (ATMS Co., Ltd., Tokyo, Japan), and p values of less than 0.05 were regarded as significant. Overall study design was approved by the Ethical Committee of Kohnan Hospital 2019.