Brain tumours are a serious concern among both physicians and patients. The most feared brain tumour is glioblastoma (GBM) due to its heterogeneous histology, substantial invasive capacity, and rapid postsurgical recurrence. Even in cases of early management consisting of surgery, chemo-, and radiotherapy, the prognosis is still poor, with an extremely short survival period. Consequently, researchers are trying to better understand the underlying pathways involved in GBM development in order to establish a more personalised approach. The latest focus is on molecular characterisation of the tumour, including analysis of extracellular vesicles (EVs), nanostructures derived from both normal and pathological cells that have an important role in intercellular communication due to the various molecules they carry. There are two types of EV based on their biogenesis, but exosomes are of particular interest in GBM. Recent studies have demonstrated that GBM cells release numerous exosomes whose cargo provides them the capacity to facilitate tumour cell invasion and migration, to stimulate malignant transformation of previously normal cells, to increase immune tolerance towards the tumour, to induce resistance to chemotherapy, and to enhance the GBM vascular supply. As exosomes are specific to their parental cells, their isolation would allow a deeper perspective on GBM pathogenesis. A new era of molecular manipulation has emerged, and exosomes are rapidly proving their value not only as diagnostic and prognostic markers, but also as tools in therapies specifically targeting GBM cells. Nonetheless, further research will be required before exosomes could be used in clinical practice. This review aims to describe the structural and functional characteristics of exosomes and their involvement in GBM development, diagnosis, prognosis and treatment.

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Patient positioning is a crucial step in neurosurgical interventions This is the responsibility of both the neurosurgeon and the anesthesiologist. Patient safety, surgeon’s comfort, choosing an optimal trajectory to the lesion, reducing brain tension by facilitating venous drainage, using gravitation to maintain the lesion exposed and dynamic retraction represent general rules for correct positioning. All bony prominences must be protected by silicone padding. The head can be positioned using a horseshoe headrest or three pin skull clamp, following the general principles: avoiding elevating the head above heart more than 30 degrees, avoiding turning the head to one side more than 30 degrees and maintaining 2 to 3 finger breaths between chin and sternum. Serious complications can occur if the patient is not properly positioned so this is why great care must be paid during this step of the surgical act.

Objective: The purely transnasal endoscopic approach has taken in the last decade a paramount importance in the treatment of pituitary adenomas, but some authors have been linked it to an increase in vascular complications. The aim of this paper is to provide a stepwise description of the vascular risks and steps required to avoid them.Method: We present the minimal invasive technique used by the senior author in over 900 transnasal purely endoscopic approaches focusing on the relevant vascular landmarks, preoperative and operative steps taken in order to avoid vascular injury and the management of vascular injury from a multitude of sources.Conclusion: Endoscopy has brought a wider field of view, with numerous vascular structures well inside the operating field. This represents control but also higher risk. Solid knowledge of the skull base anatomy and proper preoperative imaging coupled with an experienced surgeon can greatly reduce the vascular risks associated with surgery.