Adamantinomatous craniopharyngioma: evolution in the management.

BACKGROUND: In spite of the continuous progresses in pediatric neurosurgery, adamantinomatous craniopharyngioma (AC) remains a challenging tumor due to its proximity to optic pathways, pituitary gland, hypothalamus, and Willis' circle, which can result in significant endocrine, cognitive, and neurological morbidity after treatment with subsequent impact on the patient's quality of life (QoL). The relevance that QoL has today explains the changes in the management of AC observed over the time. The goal of the present article is to provide a historical background, to show the milestones in the changes of the AC treatment, and to analyze the current main options to manage such a challenging tumor. MATERIAL AND METHODS: The pertinent literature has been reviewed. Moreover, a comparison between the past and recent personal series is reported. RESULTS: Three main eras have been identified. The first (named Cushing era) was characterized by the need to realize a harmless surgery and to define the best way to approach AC; the second (microscope era) was characterized by a tremendous technical and technological development, with remarkable results in term of safe tumor resection and control but relatively poor QoL outcomes; and the third one (current period) is characterized by an increasing integration between surgery and adjuvant treatments, with relatively minor tumor control but significant improvement of QoL (comparable overall survival). The authors' experience reflects these changes. Two groups of children were compared: 52 cases (mean follow-up: 17.5 years) belong to the historical series (group 1, 1985-2003, aggressive surgical management) and 41 (mean follow-up: 8.5 years) to the current one (Group 2, 2004-2021, integrated management). No significant differences between the two groups were detected about recurrence rate, surgical mortality, and overall survival. However, Group 2 showed significant lower rates of postoperative panhypopituitarism, obesity, and visual deterioration. CONCLUSIONS: Radical surgery allows for a good AC control with a low rate of recurrence but high risk of permanent morbidity. Despite the greater number of recurrences and surgeries, the more conservative policy, based on a combination of treatments, seems to provide the same tumor control with a better QoL. The advances in trans-nasal and trans-ventricular endoscopy, in proton therapy and in the management of the AC cyst are the main factors that allowed such an improvement.

Computer tomography-based quantitative analysis of the orbital proptosis severity in infants with syndromic craniosynostosis: case-control study.

PURPOSE: Evaluation of orbital proptosis and sutural synostosis pattern along the coronal ring in craniofaciosynostosis patients with or without fibroblastic growth factor receptor 2 (FGFR2) mutation. METHODS: High-resolution computer tomography was used to assess, in children with or without FGFR2 mutation, the early synostotic involvement of the "major" and "minor" sutures/synchondroses of the coronal arch along with the following orbital parameters: interorbital angle, bone orbital cavity volume, globe volume, ventral globe volume, ventral globe index. RESULTS: Infants with FGFR2 mutation showed an increased number of closed minor sutures/synchondroses along the posterior coronal branch while both groups showed a comparable synostotic involvement of the minor sutures of the anterior coronal branch. FGFR2 infants with posterior coronal branch synostotic involvement showed a higher degree of proptosis due to both reduced bony cavity volume and increased globe volume (p<0.05). CONCLUSIONS: Our data show that FGFR2 mutation together with posterior coronal branch synostotic involvement has a synergic effect in causing a more severe degree of orbital proptosis.

Craniofacial Sutural Pattern and Surgical Management in Patients With Different Degrees of Trigonocephaly Severity.

The aim of this study was to identify quantitative tools to classify the severity of trigonocephaly to guide surgical management and predict outcome. METHODS: We reviewed high-resolution computed tomography images of 59 patients with metopic synostosis. We assessed the craniofacial sutural pattern as well as interfrontal and metopic angles, and we related the frontal angulation degree with the sutural pattern, the surgical management, and clinical outcome. RESULTS: We identified 3 groups according to the severity of trigonocephaly. No difference was found between the sutural pattern of nasion complex and severity, whereas the closure of zygomatic maxillary sutures increased with the severity degree (P < 0.05). The operative management was related to the severity degree (P < 0.001) and to the reduced age (P = 0.009). CONCLUSIONS: Interfrontal and metopic angles are complementary measurements to evaluate with high accuracy the degree of frontal angulation. In preoperative assessment, they may guide surgery decision in particular when the choice is not straightforward.

Cerebellar mutism: the predictive role of preoperative language evaluation.

BACKGROUND: The association between preoperative language impairment and development of cerebellar mutism after surgical treatment of posterior fossa tumors has gained increasing interest in recent years based on the concept that both local compression/infiltration of the infratentorial periventricular anatomical structures involved in speech and language, as well as an increased distraction of supratentorial periventricular anatomical structures, due to an associated hydrocephalus, involved in the coordination of speech circuits, might lead to the subclinical presence of language disturbances already at diagnosis, predicting the development of a cerebellar mutism syndrome after tumor removal. METHODS: A thorough review of the literature on the subject has been performed, together with a review of our institutional experience reporting the related long-term (10 years) results. RESULTS AND CONCLUSIONS: According to our institutional experience, 20/70 (28.5%) children presented preoperative language impairment and developed cerebellar mutism after surgery. A residual impairment persists in 75% of the cases at a follow-up of 2 years, and in 50% of the cases at 10 years, a finding which actually depicts cerebellar mutism no more as a transient deficit but among long-term sequelae. The appearance of complex dysarthria in the postoperative period is a negative prognostic factor for the long-term persistence of speech disturbances.

Orbito-facial dysmorphology in patients with different degrees of trigonocephaly severity: quantitative morpho-volumetric analysis in infants with non-syndromic metopic craniosynostosis.

PURPOSE: Craniofacial dysmorphology varies significantly along a wide spectrum of severity in metopic cranial synostosis (MCS). This study aimed to quantify craniofacial changes, in MCS, to investigate their relationships with the severity of trigonocephaly. METHODS: By combining the metopic ridge and interfrontal angles, we identified three groups of trigonocephaly severity (mild group n.14, moderate group n.19, severe group n.18). We perform a quantitative analysis using high-resolution CT images evaluating (1) cranial fossae dimensions; (2) vault indices and ratios: interparietal/ intercoronal (IPD/ICD), interparietal/intertemporal (IPD/ITD), cephalic index, vertico-longitudinal index; (3) orbito-facial distances (midfacial depth, maxillary height, upper facial index, orbital distances, globe protrusions), maxilla and orbital volumes; (4) supratentorial (ICV) and infratentorial (PCFV) cranial volumes and supratentorial (WBV) and infratentorial (PCFBV) brain volumes. RESULTS: In all groups, middle skull base lengths and upper midface index were increased. In moderate and severe groups: anterior hemifossa lengths were reduced, IPD/ICD and vertico-longitudinal index were changed; midfacial depth, anterior, mild, and lateral interorbital distances were reduced; globe protrusions were increased. The comparison between moderate and severe groups showed an increase of both globe protrusions and IPD/ICD. Among all groups, ICV and WBV were reduced in the severe group. CONCLUSION: This morpho-volumetric study provides new insights in understanding the craniofacial changes occurring in infants at different severity of trigonocephaly. The increase of globe protrusions and the reduction of supratentorial volumes found in the severe group reflect the severity of trigonocephaly; these findings might have a clinical and surgical relevance.

Neurocutaneous melanocytosis (melanosis).

Neurocutaneous melanosis (NCM; MIM # 249400; ORPHA: 2481], first reported by the Bohemian pathologist Rokitansky in 1861, and now more precisely defined as neurocutaneous melanocytosis, is a rare, congenital syndrome characterised by the association of (1) congenital melanocytic nevi (CMN) of the skin with overlying hypertrichosis, presenting as (a) large (LCMN) or giant and/or multiple (MCMN) melanocytic lesions (or both; sometimes associated with smaller "satellite" nevi) or (b) as proliferative melanocytic nodules; and (2) melanocytosis (with infiltration) of the brain parenchyma and/or leptomeninges. CMN of the skin and leptomeningeal/nervous system infiltration are usually benign, more rarely may progress to melanoma or non-malignant melanosis of the brain. Approximately 12% of individuals with LCMN will develop NCM: wide extension and/or dorsal axial distribution of LCMN increases the risk of NCM. The CMN are recognised at birth and are distributed over the skin according to 6 or more patterns (6B patterns) in line with the archetypical patterns of distribution of mosaic skin disorders. Neurological manifestations can appear acutely in infancy, or more frequently later in childhood or adult life, and include signs/symptoms of intracranial hypertension, seizures/epilepsy, cranial nerve palsies, motor/sensory deficits, cognitive/behavioural abnormalities, sleep cycle anomalies, and eventually neurological deterioration. NMC patients may be symptomatic or asymptomatic, with or without evidence of the typical nervous system changes at MRI. Associated brain and spinal cord malformations include the Dandy-Walker malformation (DWM) complex, hemimegalencephaly, cortical dysplasia, arachnoid cysts, Chiari I and II malformations, syringomyelia, meningoceles, occult spinal dysraphism, and CNS lipoma/lipomatosis. There is no systemic involvement, or only rarely. Pathogenically, single postzygotic mutations in the NRAS (neuroblastoma RAS viral oncogene homologue; MIM # 164790; at 1p13.2) proto-oncogene explain the occurrence of single/multiple CMNs and melanocytic and non-melanocytic nervous system lesions in NCM: these disrupt the RAS/ERK/mTOR/PI3K/akt pathways. Diagnostic/surveillance work-ups require physical examination, ophthalmoscopy, brain/spinal cord magnetic resonance imaging (MRI) and angiography (MRA), positron emission tomography (PET), and video-EEG and IQ testing. Treatment strategies include laser therapy, chemical peeling, dermabrasion, and surgical removal/grafting for CMNs and shunt surgery and surgical removal/chemo/radiotherapy for CNS lesions. Biologically targeted therapies tailored (a) BRAF/MEK in NCM mice (MEK162) and GCMN (trametinib); (b) PI3K/mTOR (omipalisib/GSK2126458) in NMC cells; (c) RAS/MEK (vemurafenib and trametinib) in LCMNs cells; or created experimental NMC cells (YP-MEL).

Introduction to phacomatoses (neurocutaneous disorders) in childhood.

The Dutch ophthalmologist, Jan van der Hoeve, first introduced the terms phakoma/phakomata (from the old Greek word "ϕαχοσ" = lentil, spot, lens-shaped) to define similar retinal lesions recorded in tuberous sclerosis (1920) and in neurofibromatosis (1923). He later applied this concept: (a) to similar lesions in other organs (e.g. brain, heart and kidneys) (1932) and (b) to other disorders (i.e. von Hippel-Lindau disease and Sturge-Weber syndrome) (1933), and coined the term phakomatoses. At the same time, the American neurologist Paul Ivan Yakovlev and psychiatrist Riley H. Guthrie (1931) established the key role of nervous systems and skin manifestations in these conditions and proposed to name them neurocutaneous syndromes (or ectodermoses, to explain the pathogenesis). The Belgian pathologist, Ludo van Bogaert, came to similar conclusions (1935), but used the term neuro-ectodermal dysplasias. In the 1980s, the American paediatric neurologist Manuel R. Gomez introduced the concept of "hamartia/hamartoma" instead of phakoma/phakomata. "Genodermatoses" and "neurocristopathies" were alternative terms still used to define these conditions. Nowadays, however, the most acclaimed terms are "phacomatoses" and "neurocutaneous disorders", which are used interchangeably. Phacomatoses are a heterogeneous group of conditions (mainly) affecting the skin (with congenital pigmentary/vascular abnormalities and/or tumours), the central and peripheral nervous system (with congenital abnormalities and/or tumours) and the eye (with variable abnormalities). Manifestations may involve many other organs or systems including the heart, vessels, lungs, kidneys and bones. Pathogenically, they are explained by interplays between intra- and extra-neuronal signalling pathways encompassing receptor-to-protein and protein-to-protein cascades involving RAS, MAPK/MEK, ERK, mTOR, RHOA, PI3K/AKT, PTEN, GNAQ and GNA11 pathways, which shed light also to phenotypic variability and overlapping. We hereby review the history, classification, genomics, clinical manifestations, diagnostic criteria, surveillance protocols and therapies, in phacomatoses: (1) predisposing to development of tumours (i.e. the neurofibromatoses and allelic/similar disorders and schwannomatosis; tuberous sclerosis complex; Gorlin-Goltz and Lhermitte-Duclos-Cowden syndromes); (2) with vascular malformations (i.e. Sturge-Weber and Klippel-Trenaunay syndromes; megalencephaly/microcephaly-capillary malformation syndromes; CLOVES, Wyburn-Mason and mixed vascular nevus syndromes; blue rubber bleb nevus syndrome; hereditary haemorrhagic telangiectasia); (3) with vascular tumours (von Hippel-Lindau disease; PHACE(S)); (4) with pigmentary/connective tissue mosaicism (incontinentia pigmenti; pigmentary/Ito mosaicism; mTOR-related megalencephaly/focal cortical dysplasia/pigmentary mosaicism; RHOA-related ectodermal dysplasia; neurocutaneous melanocytosis; epidermal/papular spilus/Becker nevi syndromes; PENS and LEOPARD syndromes; encephalocraniocutaneous lipomatosis; lipoid proteinosis); (5) with dermal dysplasia (cerebellotrigeminal dermal dysplasia); and (6) with twin spotting or similar phenomena (phacomatosis pigmentovascularis and pigmentokeratotica; and cutis tricolor).

Multimodal assessment of motor pathways and intracortical connections in functional hemispherectomy.

PURPOSE: For selected children with medically intractable epilepsy, hemispherectomy can be an excellent treatment option and its efficacy in achieving seizure freedom or reduction in seizure frequency has been shown in several studies, but patients' selection could not be straightforward and often it is taken on subjective basis. We described a multimodal approach to assess patient eligible for hemispherectomy and possibly predicting post-surgical outcomes. METHODS: We describe pre- and post-surgical clinical features along with neuroradiological results by magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), MR-tractography (MRT), and neurophysiological study by single and paired pulses transcranial magnetic stimulation (TMS) in a child with cerebral palsy with epileptic encephalopathy, eligible for epilepsy surgery. RESULTS: Presurgical TMS evaluation showed a lateralization of motor function on the left motor cortex for both arms, and results were confirmed by MRI studies. Interestingly, after surgery, both epilepsy and motor performances improved and TMS showed enhancement of intracortical inhibition and facilitation activity. CONCLUSION: Functional hemispherectomy is an effective treatment for drug-resistant epilepsy, and multimodal presurgical assessment may be a useful approach to guide surgeons in selecting patients. Moreover, pre- and post-surgical evaluation of these patients may enhance our understanding of brain plasticity phenomena.

Chiari type I and hydrocephalus.

PURPOSE: The association between Chiari type I malformation (CIM) and hydrocephalus raises a great interest because of the still unclear pathogenesis and the management implications. The goal of this paper is to review the theories on the cause-effect mechanisms of such a relationship and to analyze the results of the management of this condition. METHODS: A review of the literature has been performed, focusing on the articles specifically addressing the problem of CIM and hydrocephalus and on the series reporting about its treatment. Also, the personal authors' experience is briefly discussed. RESULTS: As far as the pathogenesis is concerned, it seems clear that raised intracranial pressure due to hydrocephalus can cause a transient and reversible tonsillar caudal ectopia ("pressure from above" hypothesis), which is something different from CIM. A "complex" hypothesis, on the other hand, can explain the occurrence of hydrocephalus and CIM because of the venous engorgement resulting from the hypoplasia of the posterior cranial fossa (PCF) and the occlusion of the jugular foramina, leading to cerebellar edema (CIM) and CSF hypo-resorption (hydrocephalus). Nevertheless, such a mechanism can be advocated only in a minority of cases (syndromic craniosynostosis). In non-syndromic CIM subjects, the presence of hydrocephalus could be explained by an occlusion of the basal CSF pathways, which would occur completely in a minority of cases (only 7-10% of CIM patients show hydrocephalus) while it would be partial in the remaining cases (no hydrocephalus). This hypothesis still needs to be demonstrated. As far as the management is concerned, the strategy to treat the hydrocephalus first is commonly accepted. Because of the "obstructive" origin of CIM-related hydrocephalus, the use of endoscopic third ventriculostomy (ETV) is straightforward. Actually, the analysis of the literature, concerning 63 cases reported so far, reveals very high success rates of ETV in treating hydrocephalus (90.5%), CIM (78.5%), and syringomyelia symptoms (76%) as well as in giving a radiological improvement of both CIM (74%) and syringomyelia (89%). The failures of ETV were not attributable to CIM or syringomyelia. Only 11% of cases required PCF decompression after ETV. CONCLUSIONS: The association between CIM and hydrocephalus probably results from different, multifactorial, and not yet completely understood mechanisms, which place the affected patients in a peculiar subgroup among those constituting the heterogeneous CIM population. ETV is confirmed as the best first approach for this subset of patients.

The unseen third dimension: a novel approach for assessing head shape severity in infants with isolated sagittal synostosis.

PURPOSE: This study aimed to develop a novel approach to assess the severity of skull dysmorphology in infants with isolated sagittal synostosis (ISS) and its relationship with the surgical results. METHODS: We divided 66 infants with ISS into three groups by combining the scaphocephalic (SSI-A) and platycephalic (VLI) indices as descriptors of the relation between length, width, and height. We evaluated each skull for morphology as hyperdolichocephalic (< 66%) versus dolichocephalic (66-77%) and as hyperplatycephalic (< 78%) versus platycephalic skull (78-85%). A score system was developed as follows: 2 points for values < 66% and < 78% and 1 point for values between 66 and 77% and 78 and 85% in SSI-A and VLI, respectively. The overall score was calculated and it was used to classify our patients on a 4-point ordinal scale, according to the severity of head shape (2 = mild, 3 = moderate, 4 = severe). RESULTS: Thirty-two infants resulted in mild group, 17 in moderate group, and 17 in severe group. SSI-A and VLI were reduced according to the severity of ISS. We demonstrated a positive correlation between SSA-A and VLI in mild subgroup of patients while we found a negative correlation between SSA-A and VLI in moderate and in severe subgroups. Moreover, a positive correlation was found between severe subgroup and Sloan III class of surgical results. CONCLUSION: This study describes a simple tool to better classify infants with ISS, considering the three-dimensional morphology of the skull, because it evaluates both the dolichocephalic and platycephalic component.

Quantitative analysis of cranial-orbital changes in infants with anterior synostotic plagiocephaly.

PURPOSE: The effects of premature fusion of one coronal suture cause skull and orbital alterations in term of side-to-side asymmetry. This study aimed to quantify the cranio-orbital complex changes related to the severity of skull base dysmorphology in patients with unicoronal synostosis. METHODS: Twenty-four infants affected by unicoronal synostosis were subdivided in three subgroups according to the severity of skull base deformity and their high-resolution CT images were quantitatively analyzed (groups IIa, IIb, III). Dimensions of cranial fossae, intracranial volume (ICV), ICV synostotic and ICV non synostotic side, whole brain volume (WBV), orbital volumes (OV), ICV/WBV, ICVsynostotic/ICVnon-synostotic, and OVsynostotic/OVnon-synostotic were evaluated. RESULTS: Asymmetry and reduction in the growth of the anterior and middle fossae were found in all groups while asymmetry of the posterior cranial fossa was found only in IIb and III groups. In all groups, ICV, WBV, and ICV/WBV were not significantly different while ICVsynostotic/ICVnon-synostotic and OVsynostotic/OVnon-synostotic resulted significant difference (p < 0.05). ICVsynostotic side resulted reduction only in group III. OV on the synostotic side was not significantly reduced although a trend in progressively reducing volumes was noted according to the severity of the group. CONCLUSION: Skull and orbital changes revealed a side-to-side asymmetry but the effects of the premature synostosis were more severe in group III suggesting an earlier timing of premature unicoronal synostosis in group III with respect to the other groups. The assessment of the skull base deformity might be an indirect parameter of severity of skull orbital changes and it might be useful for surgical planning.

Pediatric intracranial primary anaplastic ganglioglioma.

BACKGROUND: Primary intracranial anaplastic gangliogliomas are rare tumors in the pediatric patient group. Most of them present with symptoms of elevated pressure or symptomatic epilepsy. Extraaxial location is far more common than axial location. On MRI examination, they mimic pilocytic astrocytomas. The outcome after surgery depends mainly on the possible amount of surgical resection, and oncological therapy is necessary to prevent recurrence of the disease. CASE REPORT: An 11-year-old boy presented with headache and double vision due to obstructive hydrocephalus. MRI of the brain revealed an axial partially contrast enhancing lesion in the quadrigeminal plate extending from the cerebellum to the pineal gland and causing hydrocephalus. Subtotal removal of the lesion was performed, and the diagnosis of an anaplastic ganglioglioma was established and confirmed by the reference center. At the latest follow up (3 months), the boy is without any neurological symptoms and scheduled for radiation therapy as well as chemotherapy.

Correction to: Sphenoid dysplasia in neurofibromatosis type 1: a new technique for repair.

The published version of this article unfortunately contained an error. All names of the authors have been published incorrectly. Given in this article are the corrected author names.

Problems of reconstructive cranioplasty after traumatic brain injury in children.

Cranial repair after traumatic brain injury in children is still burdened by unsolved problems and controversial issues, mainly due to the high rate of resorption of autologous bone as well as the absence of valid alternative material to replace the autologous bone. Indeed, inert biomaterials are associated to satisfactory results in the short period but bear the continuous risk of complications related to the lack of osteointegration capacity. Biomimetic materials claiming osteoconductive properties that could balance their mechanical limits seem to allow good cranial bone reconstruction. However, these results should be confirmed in the long term and in larger series. Further complicating factors that may affect cranial reconstruction after head injury should be identified in the possible associated alterations of CSF dynamics and in difficulties to manage the traumatic skin lesion and the surgical wound, which also might impact on the cranioplasty outcome. All the abovementioned considerations should be taken into account when dealing with the cranial reconstruction after decompressive craniectomy in children.

Myelomeningocele Repair: Surgical Management Based on a 30-Year Experience.

BACKGROUND: Myelomeningocele (MMC) is a rare but severe spinal defect resulting from a failed neurulation process. Surgical repair is a delicate procedure that needs accurate neuroanatomical knowledge and adequate surgical planning. MATERIALS AND METHODS: The authors report on the main problems of the surgical management of this type of dysraphism. The technique used for reconstruction, and the management strategies, are analyzed according to the authors' experience with more than 600 cases, in comparison with the relevant literature. RESULTS: Tip and tricks of more than 30 years of MMC surgical management are reported, with special mention of the timing of surgery, the management of early hydrocephalus, and the principles of the repair, from the dissection to the closure of five separate layers (arachnoid, dura, muscular fascia, subcutaneous layer, skin). CONCLUSIONS: Accuracy and attention to the reconstruction are crucial for achieving good results and avoiding perioperative complications.

Cavum septi pellucidi cysts: a survey about clinical indications and surgical management strategies.

INTRODUCTION: Cavum septi pellucidi (CSP) cysts have a very low incidence (0.04%). Symptomatic patients usually present aspecific symptoms. For this reason, the management of these patients is still debated. MATERIALS AND METHODS: We selected the case of a ten year old patient, with a clinical history of frontal morning headaches and difficulty in concentration. Brain MRI documented a septum pellucidum cyst and a moderate biventricular dilation. We submitted the case, and a questionnaire concerning indications to surgery and management options to an international group of 54 pediatric neurosurgeons, analyzing the results and comparing them with the current literature. RESULTS: The majority of the participants (50%) indicated as appropriate at the early stage only a clinical observation. In case of persistence of clinical symptoms, 58% opted for intracranial pressure (ICP) monitoring, which, if raised, was considered by 91% as an adequate indication to proceed with surgical treatment. A total of 98% of the participants indicated endoscopic fenestration of the cyst as the preferred surgical strategy. CONCLUSIONS: The management of symptomatic patients with CSP cyst is controversial. Our results suggest that in most of the patients with aspecific symptoms, clinical observation and eventually ICP monitoring are adequate to identify patients for surgery.

Iatrogenic intradiploic cerebrospinal fluid collection.

BACKGROUND: Cases of intradiploic cerebrospinal fluid (CSF) collections have been previously reported in the literature with various underlying causes. We focus specifically on the iatrogenic cases of this rare but possible neurosurgical complication discussing the possible pathophysiological mechanisms and management strategy. CASE DESCRIPTION: A 14-year-old boy was admitted in our institute with recurrent headache and worsening attention deficits. He was previously treated twice for a Chiari malformation type I. The performed imaging showed the persisting lower position of the cerebellar tonsils with a syrinx within the cervical spinal cord and a fluid collection within the occipital bone with thinning of outer and inner table. Occipital bone decompression with resection of the intradiploic cavity and enlarging duraplasty was performed. Postoperative imaging confirmed the removal of the iatrogenic-induced focal bone alteration. DISCUSSION AND CONCLUSION: Iatrogenic intradiploic focal fluid accumulation can occur when a dural defect combines with an inner table defect of the calvaria or vertebral bones. Though rare, such a complication should be taken into account when postoperative imaging suggests a focal fluid collection inside the theca. The surgical excision of the lesion is mandatory due to the natural history of progression.

Neurosurgical tools to extend tumor resection in pediatric hemispheric low-grade gliomas: iMRI.

INTRODUCTION: The treatment of low-grade gliomas (LGGs) in pediatric age is still controversial. However, most authors report longer life expectancy in case of completely removed cerebral gliomas. Intraoperative magnetic resonance imaging (iMRI) is increasingly utilized in the surgical management of intra-axial tumor in adults following the demonstration of its effectiveness. In this article, we analyze the management of LGG using iMRI focusing on its impact on resection rate and its limits in the pediatric population. METHODS: We performed review of the literature regarding the treatment of LGG using iMRI focusing on its impact on resection rate and its limits in the pediatric population. Some exemplary cases are also described. RESULTS: Intraoperative MRI allowed extension of tumor resection after the depiction of residual tumor at the intraoperative imaging control from 21 to 52 % of the cases in the published series. Moreover, the early reoperation rate was significantly lower when compared with the population treated without this tool (0 % vs 7-14 %). Some technical difficulties have been described in literature regarding the use of iMRI in the pediatric population especially for positioning due to the structure of the headrest coil designed for adult patients. CONCLUSION: The analysis of the literature and our own experience with iMRI in children indicates significant advantages in the resection of LGG offered by the technique. All these advantages are obtained without elongation of the surgical times or increased risk for complications, namely infection. The main limit for a wider diffusion of iMRI for the pediatric neurosurgical center is the cost required, for acquisition of the system, especially for high-field magnet, and the environmental and organizational changes necessary for its use.

Arachnoid cyst: a further anomaly associated with Kallmann syndrome?

BACKGROUND: Kallmann syndrome (KS) is defined by the association of hypogonadotropic hypogonadism and anosmia. It is characterized by a significant clinical and genetic heterogeneity; actually, it may present several non-reproductive non-olfactory anomalies, and all the ways of genetic transmission can be involved in the inheritance of the disease. Although six pathogenesis-related genes have been identified so far, KS remains sporadic in 70 % of the cases, and the genetic diagnosis is not available for all of them. The purpose of this paper is to present a further disease that can enrich the wide spectrum of KS variability, that is cerebral arachnoid cyst. CASE DESCRIPTION: This 11-year-old boy presented with the typical characteristics of KS together with those related to a sylvian arachnoid cyst. He was admitted because of worsening headache. At the admission, the physical examination revealed eunuchoid aspect, micropenis, previous cryptorchidism, and anosmia. MRI pointed out a large, left sylvian arachnoid cyst, agenesia of the olfactory bulbs/tracts complex, and hypoplasia of the left olfactory sulcus. The child was operated on by endoscopic fenestration of the cyst, followed by transient external drainage for subdural hygroma and microscopic fenestration for recurrence of the cyst. His statural growth is normal but the sexual development still delayed in spite of hormone replacement therapy. CONCLUSION: According to the present and the other four cases in the literature, arachnoid cyst should be included among the anomalies possibly accompanying KS date although this association seems to be occasional as far as embryogenesis and physiopathology are concerned.

Recurrent adult-type fibrosarcoma of the frontal bone in a child.

INTRODUCTION: Primary, adult-type bone fibrosarcoma is an uncommon, malignant spindle-cell tumor of fibroblastic origin, rarely affecting children. Most frequently diagnosed among bone malignancies in the past, improved diagnostic techniques and further restrictive classification criteria have currently made the diagnosis of fibrosarcoma very unusual. CASE REPORT: We hereby report the case of a 7-year-old child with a right frontal swelling mass. A computed tomography scan showed an osteolytic lesion of the right frontal bone, involving the diploe and the outer table of the skull. An en bloc surgical excision, followed by a thorough immunohistological evaluation, led to the diagnosis of fibroblastic proliferation, with low cellularity and minimal atypias. The patient had four recurrences during the 4-year follow-up. With an increasing histological grade at recurrences, a diagnosis of adult-type fibrosarcoma was made. CONCLUSION: To the best of the authors' knowledge, this is the first reported case of an adult-type fibrosarcoma arising in the frontal bone of a child.