Alberto Feletti

Malignant progression in pleomorphic xanthoastrocytoma: Personal experience and review of the literature

Pleomorphic xanthoastrocytoma (PXA) is a rare primary low-grade astrocytic tumor, recently classified as a neuroglial tumor. It generally occurs in children and young adults and shows benign behaviour (WHO II), although an anaplastic variant and malignant potential have been described. Pleomorphic xanthoastrocytomas with malignant transformation have been reported in three out of eight patients operated on for this type of tumor in our department in the last 15 years. The three patients were two adult women and a child, the primary tumors were located in the cortex of the right temporal lobe, and treatment consisted of complete surgical resection. Histological examination revealed simple PXA in two patients and a PXA with anaplastic foci in the other. Mean recurrence time was 5.7 years, with the original xanthoastrocytoma evolving to glioblastoma in two cases and anaplastic astrocytoma in the third. All three patients underwent a second operation, followed by adjuvant therapies. Two died from tumor progression and one from brain edema after intracerebral haemorrhage. A review of the available PXA literature dating back to 1979 revealed 16 cases of primary anaplastic astrocytoma and 21 cases of PXA with malignant transformation. Our experience adds three more cases of malignant transformations, outlining once again the potential malignancy of pleomorphic xanthoastrocytomas and the fact that prognosis in these cases is the same as for primary anaplastic astrocytoma and glioblastoma. Analysis of glioneuronal markers, Ki67 and p53 in all pleomorphic xanthoastrocytomas did not prove to be a discriminating factor to identify a subgroup of xanthoastrocytomas prone to malignancy. Accordingly, these tumors demand close long-term clinical and radiological follow-up.

Primary obstruction of the fourth ventricle outlets: neuroendoscopic approach and anatomic description.

OBJECTIVEPrimary obstruction of the foramina of Magendie and Luschka is an uncommon and still unclear cause of noncommunicating hydrocephalus. The aim of this work is the description, for the first time, of the inner aspect of these velar obstructions of the fourth ventricle outlets and the demonstration of the efficacy of neuroendoscopic treatment. METHODSOf 240 hydrocephalic patients treated in our institution with endoscopic third ventriculostomy, a subgroup of 10 cases with closure of the fourth ventricular outlets without associated Chiari malformation and syringomyelia was selected. In all of these cases, a transaqueductal endoscopic navigation of the fourth ventricle was performed, and the obstructed outlets were inspected. All of the clinical data and, in particular, the videotape records of endoscopic operations, as well as the cine-magnetic resonance imaging scans, were reviewed to evaluate their patency status. RESULTSVarious degrees of stenosis were found endoscopically: restriction of the Magendie contour with thick and opaque membrane, transparent spider web-like membrane, and dense membrane with fissures acting as valves. Endoscopic third ventriculostomy was effective in almost all patients, although we noticed an unforeseen high incidence of closure of the stoma. The restored normal cerebrospinal fluid flux after ventriculocisternostomy and magendieplasty was demonstrated by comparative study of cerebrospinal fluid flow measurements by cine-magnetic resonance imaging. CONCLUSIONThis report demonstrates the effectiveness of neuroendoscopic third ventriculostomy as well as magendiestomy in cases of tetraventricular hydrocephalus attributable to primary obstruction of the outlets of the fourth ventricle and, for the first time, presents direct images of various types of outlet obstructive pathology.

Dumbbell-shaped C-2 psammomatous melanotic malignant schwannoma. Case report and review of the literature.

The authors present the case of a dumbbell-shaped malignant psammomatous melanotic schwannoma of the upper cervical spine involving the C-2 sensory root. The family of the patient had a history of other malignant stromal tumors, without the Carney complex genetic pattern. The 30-year-old female patient complained of experiencing cervical pain and cervical muscle contractions for 6 months, and was admitted to the hospital. The cervical T1-weighted magnetic resonance (MR) images revealed the presence of a slightly hyperintense C2-3 intra-extradural lesion, moderately enhancing, which had eroded and enlarged the intervertebral foramen. The patient workup also included computed tomography scans and angiography. A posterior approach was used to perform a C2-3 hemilaminectomy, including opening of the dura mater and gross-total removal of the lesion. Histopathological examination of the lesion revealed it to be a malignant psammomatous melanotic schwannoma. The cerebrospinal MR image of the patient obtained at the 12-month follow-up examination demonstrated the presence of tumor progression into the subarachnoid space at the C-3 level. The strong malignancy potential of the lesion must be considered in the future management of the patient, especially due to the presence in the family of other stromal tumors such as gastrointestinal-stromal tumors and malignant melanomas. The authors review all the literature concerning melanotic schwannomas and report 105 cases of melanotic schwannoma that were not related to the Carney complex. The particular focus of their review is on the characteristics of the malignant progression of melanotic schwannoma, such as local recurrences, metastasis, and survival rate.

Dynamic monitors of brain function: a new target in neurointensive care unit.

IntroductionSomatosensory evoked potential (SEP) recordings and continuous electroencephalography (EEG) are important tools with which to predict Glasgow Outcome Scale (GOS) scores. Their combined use may potentially allow for early detection of neurological impairment and more effective treatment of clinical deterioration.MethodsWe followed up 68 selected comatose patients between 2007 and 2009 who had been admitted to the Neurosurgical Intensive Care Unit of Treviso Hospital after being diagnosed with subarachnoid haemorrhage (51 cases) or intracerebral haemorrhage (17 cases). Quantitative brain function monitoring was carried out using a remote EEG-SEP recording system connected to a small amplification head box with 28 channels and a multimodal stimulator (NEMO; EBNeuro, Italy NeMus 2; EBNeuro S.p.A., Via P. Fanfani 97/A - 50127 Firenze, Italy). For statistical analysis, we fit a binary logistic regression model to estimate the effect of brain function monitoring on the probability of GOS scores equal to 1. We also designed a proportional odds model for GOS scores, depending on amplitude and changes in both SEPs and EEG as well as on the joint effect of other related variables. Both families of models, logistic regression analysis and proportional odds ratios, were fit by using a maximum likelihood test and the partial effect of each variable was assessed by using a likelihood ratio test.ResultsUsing the logistic regression model, we observed that progressive deterioration on the basis of EEG was associated with an increased risk of dying by almost 24% compared to patients whose condition did not worsen according to EEG. SEP decreases were also significant; for patients with worsening SEPs, the odds of dying increased to approximately 32%. In the proportional odds model, only modifications of Modified Glasgow Coma Scale scores and SEPs during hospitalisation statistically significantly predicted GOS scores. Patients whose SEPs worsened during the last time interval had an approximately 17 times greater probability of a poor GOS score compared to the other patients.ConclusionsThe combined use of SEPs and continuous EEG monitoring is a unique example of dynamic brain monitoring. The temporal variation of these two parameters evaluated by continuous monitoring can establish whether the treatments used for patients receiving neurocritical care are properly tailored to the neurological changes induced by the lesions responsible for secondary damage.

Pituitary metastasis of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a malignant neuroendocrine tumor of the skin that demonstrates a remarkable tendency to metastasize. However, only a few cases of MCC brain metastases have been reported in the literature. We here present a unique case of a pituitary metastasis of MCC in a 65-year-old patient with a history of pituitary adenoma. This case is particularly novel due to the fact that the primary site of the MCC is unknown.

Peripheral trigeminal nerve field stimulation: report of 6 cases.

OBJECT Peripheral nerve field stimulation has been successfully used for many neuropathic syndromes. However, it has been reported as a treatment for trigeminal neuropathic pain or persistent idiopathic facial pain only in the recent years. METHODS The authors present a review of the literature and their own series of 6 patients who were treated with peripheral nerve stimulation for facial neuropathic pain, reporting excellent pain relief and subsequent better social relations and quality of life. RESULTS On average, pain scores in these patients decreased from 10 to 2.7 on the visual analog scale during a 17-month follow-up (range 0-32 months). The authors also observed the ability to decrease trigeminal pain with occipital nerve stimulation, clinically confirming the previously reported existence of a close anatomical connection between the trigeminal and occipital nerves (trigeminocervical nucleus). CONCLUSIONS Peripheral nerve field stimulation of the trigeminal and occipital nerves is a safe and effective treatment for trigeminal neuropathic pain and persistent idiopathic facial pain, when patients are strictly selected and electrodes are correctly placed under the hyperalgesia strip at the periphery of the allodynia region.

Neuroendoscopic aspiration of tumors in the posterior third ventricle and aqueduct lumen: a technical update.

BackgroundSmall soft ventricular tumors are good candidates for complete removal by a purely endoscopic technique. This approach is particularly interesting for lesions located in the posterior third ventricle and aqueductal lumen.MethodsWe present our method of endoscospic aspiration through direct contact between the tumor and the working channel of a flexible scope.ResultsAspiration without the intermediate use of cannulas is safe and has proved to be effective in the apparently total or partial removal of three soft tumors of different pathologies located in the third ventricle or aqueductal lumen. In one case, a second neuroendoscopy a few months later to repeat endoscopic third ventriculostomy (ETV) offered a unique opportunity to observe the absence of the tumor and the restored anatomy.ConclusionsNeuroendoscopy provides a safe, effective way to radically resect small soft tumors in these troublesome locations and can be a valuable alternative to microsurgery.

Atypical cystic meningioma overexpressing AQP1 in early infancy: case report with literature review

Meningiomas in early infancy are rare lesions, worth to be reported for their exceptional occurrence. The authors report a case of an 11‐month‐old female child with asymmetric macrocephaly due to the presence of a cystic atypical meningioma associated to bilateral subdural collections.

Adult idiopatic occlusion of Monro foramina: intraoperative endoscopic reinterpretation of radiological data and review of the literature

Abstract Adult idiopathic occlusion of the foramen of Monro (AIOFM) is a rare condition, with only few cases described in the modern literature. We propose that AIOFM may result from unilateral or bilateral occlusion of Monro foramina, as well as from progression of a monolateral hydrocephalus. Different surgical strategies may be required for effective treatment according to the type of occlusion. To date, only 12 cases of AIOFM have been reported in the literature. We report the cases of two patients, aged 20 and 47 years respectively, who presented with intracranial hypertension secondary to bilateral ventricular dilatation due to obstruction at the level of the foramen of Monro. Both patients were successfully treated with endoscopic fenestration of the primarily obstructed foramen of Monro and, in one patient, fenestration of the septum. We propose that septum pellucidum displacement could play a role in the occlusion of the second foramen of Monro. AIOFM can, therefore, result also from unilateral stenosis of Monro. The difference in AIOFM (i.e. unilateral vs bilateral) will be useful in guiding the most suitable surgical approach in this rare condition.

Dual-Image Videoangiography During Intracranial Microvascular Surgery

OBJECTIVE Indocyanine green videoangiography (ICG-VA) is a valuable tool to assess vessel and aneurysm patency during neurovascular surgical procedures. However, ICG-VA highlights vascular structures, which appear white over a black background. Anatomic relationships are sometimes difficult to understand at first glance. Dual-image videoangiography (DIVA) enables simultaneous visualization of light and near-infrared fluorescence images of ICG-VA. METHODS The DIVA system was mounted on an OPMI Pentero Flow 800 intraoperative microscope. DIVA was used during microsurgical procedures on 5 patients who were operated for aneurysm clipping and superficial temporal artery-middle cerebral artery bypass. RESULTS DIVA provides real-time simultaneous visualization of aneurysm and vessels and surrounding structures including brain, nerves, and surgical clips. Although visual contrast between vessels and background is higher with standard black-and-white imaging, DIVA makes it easier to understand anatomic relationships between intracranial structures. DIVA also provides better vision of the depth of field. CONCLUSIONS DIVA has the potential to become a widely used intraoperative tool to check patency of intracranial vessels. It should be considered as an adjunct to standard ICG-VA for better understanding of vascular anatomy in relation to surrounding structures and can have an impact on decision making during surgery.