Marcello Ravegnani

IRCCS Istituto G. Gaslini, Genova, Liguria, Italy

Are you Marcello Ravegnani?

Claim your profile

Publications (23)47.95 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECT Sinus pericranii (SP) is a rare venous anomaly abnormally connecting the intracranial dural sinuses with the epicranial veins. In the present study the authors aimed to clarify this clinicoradiological entity, define the role of angiography in its preoperative assessment, and suggest a diagnostic-therapeutic flow chart for management purposes. METHODS The authors retrospectively reviewed the clinical charts and neuroimages of 21 patients with SP. All patients underwent brain MRI, MR venography, and craniocerebral CT. Diagnostic digital subtraction angiography was performed in 19 of 21 patients, and the SPs were categorized as dominant (draining the majority of the intracranial venous outflow) or accessory (draining only a minority of the intracranial venous outflow). RESULTS SP was median or paramedian in 20 patients and lateral in 1 patient. There were 5 dominant and 14 accessory SPs. The dominant SPs were not treated. Among the patients with accessory SP, 4 were not treated, 2 underwent surgical ligature, and 8 were treated endovascularly (with either transvenous or percutaneous embolization). No complications were observed, and symptoms disappeared after treatment in all cases. CONCLUSIONS Accepted guidelines or recommendations concerning the management, diagnosis, and treatment of SP are still lacking. The authors define here a diagnostic-therapeutic flow chart, in which angiography plays a crucial role in the classification of SP and choice of the optimal treatment. Only accessory SP is amenable to treatment, whereas dominant SP must be preserved. The endovascular approach is becoming increasingly relevant and has proven to be safe and effective.
    Journal of Neurosurgery Pediatrics 10/2014; · 1.63 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aim: Glioneuronal tumors (especially gangliogliomas and dysembryoplastic neuroepithelial tumors) are an increasingly recognised cause of drug-resistant epilepsy in children. The optimal surgical strategy (lesionectomy vs. extended resection of epileptogenic peritumoral areas) to obtain seizure control has not been fully established. Our aim was to analyze the post-surgical seizure outcome in children with epileptogenic glioneuronal tumors related to lesionectomy. Methods: The clinical data were collected through a database. Video-EEG and MRI were performed in all patients pre-operatively and at the follow-up. Results: Our series included 22 patients. The age range at surgery was 10 months-16 years (mean: 6.5±4.5 years). Epilepsy duration ranged 1-78 months (mean: 11.6±17.0). There were complex partial seizures in 14 cases, simple partial seizures in 6 patients and generalized epilepsy in 2. Gross-total surgical removal was achieved in 15 (68.2%) patients. At the last follow-up (mean 4.7 years), 20 (90.9%) patients were seizure-free (Engel Class I) and two (9.1%) were Engel Class III. Six out of seven (85.7%) patients with subtotal removal were Engel Class I. Statistical analysis failed to detect any difference between seizure outcome (Engel Class) and tumor type (DNT vs. GG; P=1.00) or location (temporal vs. non temporal; P=0.51), and extension of the resection (total vs. subtotal; P=1.00). Conclusion: Primary aim of the surgery for epileptogenic glioneuronal tumors is to remove the lesion and to obtain a complete seizure control. However, if a complete tumor resection cannot be carried out, a subtotal removal of the lesion can equally provide satisfactory results.
    Minerva pediatrica 12/2013; 65(6):609-16. · 0.64 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The surface marker PROM1 is considered one of the most important markers of tumor-initiating cells, and its expression is believed to be an adverse prognostic factor in gliomas and in other malignancies. To date, to our knowledge, no specific studies of its expression in medulloblastoma series have been performed. The aims of our study were to evaluate the expression profile of the PROM1 gene in medulloblastoma and to assess its possible role as a prognostic factor. The PROM1 gene expression was evaluated by quantitative- polymerase chain reaction on 45 medulloblastoma samples by using specific dye-labeled probe systems. A significantly higher expression of PROM1 was found both in patients with poorer prognosis (P= .007) and in those with metastasis (P= .03). Kaplan-Meier analysis showed that both overall survival (OS) and progression-free survival (PFS) were shorter in patients with higher PROM1 mRNA levels than in patients with lower expression, even when the desmoplastic cases were excluded (P= .0004 and P= .002, for OS and PFS for all cases, respectively; P= .002 and P= .008 for OS and PFS for nondesmoplastic cases, respectively). Cox regression model demonstrated that PROM1 expression is an independent prognostic factor (hazard ratio, 4.56; P= .008). The result was validated on an independent cohort of 42 cases by microarray-based analysis (P= .019). This work suggests that high mRNA levels of PROM1 are associated with poor outcome in pediatric medulloblastoma. Furthermore, high PROM1 expression levels seem to increase the likelihood of metastases. Such results need to be confirmed in larger prospective series to possibly incorporate PROM1 gene expression into risk classification systems to be used in the clinical setting.
    Neuro-Oncology 05/2011; 13(5):500-8. · 6.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We prospectively followed-up 32 pediatric patients with cerebral cavernomas (CCs) to better define surgical indications in this population. Three groups of patients were identified: (a) children with macrohemorrhage (21 patients, 65.6%), (b) children with localized or diffuse headache (6 patients, 18.8%) and (c) children with epilepsy (5 patients, 15.6%). Surgery was performed in 28 out of the 32 (87.5%) subjects. New transient post-operative neurological deficits were observed in two children. One child developed a post-operative hematoma. At a median follow-up of 4years (range 1–11years), 22 out of the 28 (78.6%) operated patients were in good conditions. All operated subjects with epilepsy were seizure-free. We confirm the high risk of macrohemorrhage in pediatric CCs. Surgery is mostly recommended in accessible cavernomas, except for small, asymptomatic deep-seated CCs or for punctuate lesions without bleeding signs. KeywordsCavernoma-Cerebral cavernous malformations-Hemorrhage-Pediatric neurosurgery
    Neurological Sciences 04/2010; 31(2):117-123. · 1.41 Impact Factor
  • Acta Neuropathologica 03/2010; 119(5):651-3. · 9.73 Impact Factor
  • British Journal of Neurosurgery 03/2010; 24(3):306-8. · 0.86 Impact Factor
  • Source
    Neurological Sciences 11/2009; · 1.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Herein we report on the successful isolation and establishment of a novel, long-term, primary, neurosphere-like cell line called 1603-MED from a 5-year-old boy affected by a highly aggressive anaplastic medulloblastoma. Elaboration of the new protocol for neurosphere assay is extensively discussed, together with a complete immuno-histochemical and cytogenetic characterization of 1603-MED. Clinical course and histopathology are briefly discussed. The 1603-MED possesses a high capacity for proliferation, CD133 expression, self-renewal and differentiation, thus indicating that anaplastic medulloblastoma contains a subpopulation of cancer stem cells as observed in classic medulloblastoma. 1603-MED provides us with the first in vitro model of anaplastic medulloblastoma that may be suitable for studying both tumour progression and the genetic mechanisms related to therapy resistance, and may lead to the development and testing of chemosensitivity and new therapeutic targets.
    Neuropathology and Applied Neurobiology 07/2008; 34(3):306-15. · 4.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Germinoma arising in the bilateral basal ganglia is exceedingly rare, with only five cases reported to date. Owing to non-specific clinical findings and the frequent presence of ill-defined abnormalities without a definite tumor mass on neuroimaging, the diagnosis can be difficult. We describe a case in which magnetic resonance spectroscopy (MRS) findings suggested a tumor and supported the decision to perform biopsy of the lesion.
    Pediatric Blood & Cancer 02/2008; 50(1):177-9. · 2.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: INTRODUCTION: Cystic angiomatosis of the skull and spine is an exceptionally rare, benign vascular lesion. Both the vertebral bones and the skull may be affected. Diagnosis and treatment of this disease is multidisciplinary. DISCUSSION: Histological examination is ultimately required to make a diagnosis. When the craniocervical junction is involved, the site of biopsy should be carefully selected so as to reduce procedure-related morbidity, including cerebrospinal fluid leakage and spinal deformity. We present a case report of a 4-year-old boy with cystic angiomatosis of the skull base and upper cervical spine associated with a Chiari I malformation and provide a review of the pertinent literature.
    Child s Nervous System 07/2007; 23(6):697-700. · 1.24 Impact Factor
  • Seminars in Roentgenology 11/2006; 41(4):250-73. · 0.56 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Craniopharyngiomas are benign, partly cystic epithelial tumors that account for 5-13% of all intracranial tumors and 50% of all suprasellar masses in children. They pose several challenges to the neuroradiologist. This paper aims to focus on the main issues regarding the neuroradiological diagnosis and follow-up after treatment. Topics include (i) the imaging modalities (i.e., CT and MRI) utilized in the diagnostic workup; (ii) the neuroradiological appearance, focusing on calcifications, cystic components, contrast enhancement, and location; (iii) the relationships to adjacent structures, such as the optic chiasm, hypothalamus, third ventricle, and circle of Willis; (iv) the differential diagnosis with other tumoral and non-tumoral entities occurring in the sellar/suprasellar area; and (v) post-treatment imaging issues.
    Journal of pediatric endocrinology & metabolism: JPEM 05/2006; 19 Suppl 1:299-319. · 0.75 Impact Factor
  • Journal of pediatric endocrinology & metabolism: JPEM 05/2006; 19 Suppl 1:337-40. · 0.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Desmoplastic infantile ganglioglioma (DIG) is a rare intracranial tumor affecting newborns and infants, and generally arising in the supratentorial region. We report a case of an unusual DIG, arising at the cervico-medullary junction, with diffuse leptomeningeal seeding at diagnosis that was treated with chemotherapy (CT) and delayed partial surgery. The case we describe demonstrates that DIG can occur in the subtentorial region and can show leptomeningeal dissemination like other low-grade gliomas.
    Pediatric Blood & Cancer 01/2006; 45(7):986-90. · 2.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Spinal and spinal cord malformations are collectively named spinal dysraphisms. They arise from defects occurring in the early embryological stages of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal dysraphisms are categorized into open spinal dysraphisms (OSDs), in which there is exposure of abnormal nervous tissues through a skin defect, and closed spinal dysraphisms (CSD), in which there is a continuous skin coverage to the underlying malformation. Open spinal dysraphisms basically include myelomeningocele and other rare abnormalities such as myelocele and hemimyelo(meningo)cele. Closed spinal dysraphisms are further categorized based on the association with low-back subcutaneous masses. Closed spinal dysraphisms with mass are represented by lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category further comprises defects of midline notochordal integration (basically represented by diastematomyelia) and defects of segmental notochordal formation (represented by caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging (MRI) is the preferred modality for imaging these complex abnormalities. The use of the aforementioned classification scheme is greatly helpful to make the diagnosis.
    European Journal of Radiology 06/2004; 50(2):177-200. · 2.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Spinal cord development occurs through the three consecutive periods of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal cord malformations derive from defects in these early embryonic stages, and are collectively called spinal dysraphisms. Spinal dysraphisms may be categorized clinically into open and closed, based on whether the abnormal nervous tissue is exposed to the environment or covered by skin. Open spinal dysraphisms include myelomeningocele and other rare abnormalities such as myelocele, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are further divided into two subsets based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category involves abnormal notochordal development, either in the form of failed midline integration (ranging from complete dorsal enteric fistula to neurenteric cysts and diastematomyelia) or of segmental agenesis (caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging is the imaging modality of choice for evaluation of this complex group of disorders.
    Journal of Neuroradiology 02/2004; 31(1):3-24. · 1.24 Impact Factor
  • European Journal of Pediatric Surgery 01/1997; 6 Suppl 1:44-5. · 0.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intracranial immature teratomas (IT) are very rare germ cell tumors (GCT). The value of chemotherapy in their treatment has not been defined. A child was referred to our hospital for consultation regarding the need for adjuvant treatment after being operated upon twice (at the age of 7 months and 11 months) for a large supratentorial intracerebral mass. The patient was staged and the tumor specimens reviewed. Histology was that of an IT with no other type of malignant GCT. Considering the age, lack of any sign of residual tumor by computed tomography and magnetic resonance imaging, absence of tumor cells in the spinal fluid or elevation of tumor markers, and based on the reported poor response of such tumors to chemotherapy, a policy of "wait and see" was adopted. One month later, the child presented with a rapidly growing intracranial mass invading the cranial bones on the left side. Chemotherapy consisting of 4 cycles of carboplatin, etoposide, and bleomycin followed by another 4 cycles of ifosfamide, vincristine, and dactinomycin alternating with carboplatin and etoposide, achieved complete remission, and 24 months after discontinuation of treatment, the patient continued free of disease. This report indicates that chemotherapy may be effective therapy for intracranial IT. In our patient, chemotherapy modified the natural aggressive behavior of this disease and achieved a persistent, complete remission. Given the minimal information available in the literature concerning the response of IT to chemotherapy, this case addresses the issue of whether chemotherapy alone is adequate to treat intracranial germ cell tumors.
    Cancer 04/1996; 77(5):977-82. · 5.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The authors describe a new instrumentation for repositioning of the Brown-Roberts-Wells (BRW) stereotaxic system, useful for precise fractionated radiotherapy. A lucite ring is fixed to the patient's skull with four screws. Another ring, partially open, is then firmly connected co-axially to the lower part of the first one with four spacer-bars. The fixture permits an exact repositioning of the B.R.W. stereotaxic system, placing the target point in the linear accelerator isocenter. The preliminary technical results obtained in five children are reported and the fixture performance, advantages, and perspectives are discussed.
    Acta Neurochirurgica 02/1994; 129(1-2):92-6. · 1.55 Impact Factor
  • Minerva pediatrica 11/1992; 44(10 Suppl 1):37-42. · 0.64 Impact Factor