The extraneural spreading of gliomas is an infrequent occurrence which is not necessarily related to either tumor histology or site. This paper reports two cases, a glioblastoma and an oligodendroglioma, both presenting extradural diffusion. In the first case, where there was severe intracranial hypertension, the tumor found its way out from the neurocranium, far from the site of the operation, perforating the dura and the bone of the cranial base. In the second case, the operation may have facilitated the extraneural invasion. This unusual behaviour of glial tumors is probably less rare than presumed. It may go unnoticed if the attention is concentrated on the usually severe neurological syndrome which is present in these patients.

A patient with a completely calcified chromophobe adenoma is reported. Endocrine evaluation revealed very high prolactin levels. Such extensive calcifications in prolactin-secreting adenomas are extremely rare. The possible pathogenetic mechanisms of this association are discussed.

Multiple sclerosis rarely may present as a focal cerebral mass with clinical features and computed tomographic scan appearances of cerebral tumor. Distinguishing between these can be difficult or impossible. We report a case of a multiple sclerosis plaque involving the parietal lobe with mass effect; clinical and radiological features had led to a diagnosis of cerebral tumor.

The authors present five patients with mucocele, submitted to neurosurgery. Two had mucoceles spreading from the frontal and/or the anterior ethmoidal sinuses and had only compressive mass symptoms, either on the ocular globe or on the frontal lobe or on both. Three patients had mucoceles growing from the sphenoid and/or posterior ethmoidal sinuses. In these latter, the mass symptoms were less evident. All the patients suffered excruciating retro-ocular pain and two presented cranial nerve damage. The correct diagnosis in these cases is crucial to avoid a too aggressive treatment since these patients are generally sent to a neurosurgeon for a suspected cranial base malignancy or an invasive pituitary adenoma. The principles of a correct differential diagnosis and of operative treatment are outlined based on an analysis of the literature and the authors experience.

Spinal dural arteriovenous fistulae are the most common type of spinal vascular malformations (AVMs). They have been classified into four types: dural AVM (type I), glomus AVM (type II), juvenile AVM (type III), and intradural direct arteriovenous fistula (type IV). Intradural AVMs manifest as subarachnoid or intramedullary hemorrhages, whereas dural AVM manifest as epidural hematoma. Spinal osseous epidural arteriovenous fistula (AVF) is not a well-defined vascular abnormality in the spine and consists in a high-flow vascular lesion outside the dura or spinal canal. It is located in the extradural space involving a bone at the area of the dilated venous sac to which all the feeders converge to the margin. We describe the case of a 14-year-old girl with cervical epidural hematoma caused by a spinal epidural arteriovenous fistula.