Myxoid glioneuronal tumor: Histopathologic, neuroradiologic, and molecular features in a single center series.

BACKGROUND: Myxoid glioneuronal tumor (MGT) is a benign glioneuronal neoplasm recently introduced in the World Health Organization (WHO) classification of the central nervous system (CNS) tumors. MGTs are typically located in the septum pellucidum, foramen of Monro or periventricular white matter of the lateral ventricle. They were previously diagnosed as dysembryoplastic neuroepithelial tumors (DNT), showing histological features almost indistinguishable from classical cortical DNT. Despite that, MGTs have been associated with a specific dinucleotide substitution at codon 385 in the platelet-derived growth factor receptor alpha (PDGFRA) gene, replacing a lysine residue with either leucine or isoleucine (p. LysK385Leu/Iso). This genetic variation has never been described in any other CNS tumor. MATERIALS AND METHODS: Thirty-one consecutive tumors, previously diagnosed as DNTs at the Meyer Children's Hospital IRCCS between January 2010 and June 2021 were collected for a comprehensive study of their clinical, imaging, pathological features, and molecular profile. RESULTS: In six out of the thirty-one tumors we had previously diagnosed as DNTs, we identified the recurrent dinucleotide mutation in the PDGFRA. All six tumors were typically located within the periventricular white matter of the lateral ventricle and in the septum pellucidum. We then renamed these lesions as MGT, according to the latest WHO CNS classification. In all patients we observed an indolent clinical course, without recurrence. CONCLUSION: MGT represent a rare but distinct group of neoplasm with a typical molecular profiling, a characteristic localization, and a relative indolent clinical course.

Expression of microRNAs miR21, miR146a, and miR155 in tuberous sclerosis complex cortical tubers and their regulation in human astrocytes and SEGA-derived cell cultures.

Tuberous sclerosis complex (TSC) is a genetic disease presenting with multiple neurological symptoms including epilepsy, mental retardation, and autism. Abnormal activation of various inflammatory pathways has been observed in astrocytes in brain lesions associated with TSC. Increasing evidence supports the involvement of microRNAs in the regulation of astrocyte-mediated inflammatory response. To study the role of inflammation-related microRNAs in TSC, we employed real-time PCR and in situ hybridization to characterize the expression of miR21, miR146a, and miR155 in TSC lesions (cortical tubers and subependymal giant cell astrocytomas, SEGAs). We observed an increased expression of miR21, miR146a, and miR155 in TSC tubers compared with control and perituberal brain tissue. Expression was localized in dysmorphic neurons, giant cells, and reactive astrocytes and positively correlated with IL-1ß expression. In addition, cultured human astrocytes and SEGA-derived cell cultures were used to study the regulation of the expression of these miRNAs in response to the proinflammatory cytokine IL-1ß and to evaluate the effects of overexpression or knockdown of miR21, miR146a, and miR155 on inflammatory signaling. IL-1ß stimulation of cultured glial cells strongly induced intracellular miR21, miR146a, and miR155 expression, as well as miR146a extracellular release. IL-1ß signaling was differentially modulated by overexpression of miR155 or miR146a, which resulted in pro- or anti-inflammatory effects, respectively. This study provides supportive evidence that inflammation-related microRNAs play a role in TSC. In particular, miR146a and miR155 appear to be key players in the regulation of astrocyte-mediated inflammatory response, with miR146a as most interesting anti-inflammatory therapeutic candidate.

Meningitis complicated by subdural empyema and deafness caused by pneumoccoccal serotype 7F in a 17-month-old child: a case report.

Despite the availability of effective antibacterial agents and vaccines, pneumococcal meningitis and sepsis are still associated with high mortality rates and a high risk of neurological sequelae. We describe the case of a 17-month-old boy vaccinated with heptavalent pneumococcal conjugate vaccine (PCV7) who developed bacterial meningitis complicated by subdural empyema and deafness caused by Streptococcus pneumoniae serotype 7F. The 7F strain is not contained in PCV7 (the only vaccine on the market at the time of the onset of meningitis) but is included in the new pediatric 13-valent PCV, which may therefore prevent cases such as this in the future.

Congenital glioblastoma.

We describe the case a 2-day-old female with congenital glioblastoma. Total resection was followed by adjuvant and high dose chemotherapy, as indicated by the current Italian infant protocol. The child is alive and well 18 months after diagnosis. A review of 67 selected congenital brain tumors showed the mortality rate was 82%. Even though the majority of patients had glioblastoma, only 5/67 had received adjuvant therapy. To ensure optimal outcomes, we recommend total or subtotal surgical resection, followed by adjuvant and high dose chemotherapy. Given the lack specific protocols for congenital brain tumors an international consensus seems to be needed, starting with congenital glioblastoma.

O6-Methylguanine-DNA-methyltransferase in recurring anaplastic ependymomas: PCR and immunohistochemistry.

Ependymomas are the third most common brain tumor in children. The post surgical management is controversial. There are no convincing data on an effective role for chemotherapy. O(6)-Methylguanine-DNA-Methyltransferase (MGMT) is a DNA repair protein considered to be a chemosensitivity predictor. Hypermethylation of the MGMT gene promoter is an important cause of MGMT inactivation. We evaluated the MGMT gene promoter methylation and the immunohistochemical MGMT protein expression in 12 recurrent anaplastic ependymomas affecting children. Our purpose was to investigate the molecular rationale of the administration of alkylating agents to children affected by recurrent anaplastic ependymomas. All ependymomas lacked MGMT promoter hypermethylation and 9 (75%) showed high MGMT protein expression (>50% tumoral cells). Differences between different recurrences in the same patient were not observed. These results may indicate MGMT as a factor of chemoresistance to alkylating drugs in anaplastic ependymomas and support the uncertainties regarding the actual benefit of chemotherapy for patients with anaplastic ependymomas.

Occipital pilomyxoid astrocytoma in a 14-year-old girl--case report.

Pilomyxoid astrocytoma is a recently described tumor. Its most typical morphological characteristics are an angiocentric astrocytic proliferation embedded in a myxoid background. The behavior seems to be unfavorable due to the reported high rate of local recurrence. The earlier studies indicated that pilomyxoid astrocytoma typically affects young children and arises in the hypothalamic/chiasmatic region. We report a case of a 14-year-old patient with a 6-year history of absence seizure. Magnetic resonance imaging showed a right occipital lesion of approximately 3 cm in diameter. The patient underwent the surgical procedure with gross total excision. Histologically, the tumor was mainly composed of a monomorphous population of bipolar elongated piloid cells radially arranged around thin-walled blood vessels in a prominent myxoid background. There were focal hemorrhagic foci but no bona fide evidence of tumor necrosis or mitoses. Rosenthal fibers and eosinophilic granular bodies were not observed. The postoperative course was uneventful. No adjuvant therapy was administered. The patient is alive and well at 18-month follow-up. The case presented provides evidence that pilomyxoid astrocytoma can occur at a later age and can arise in regions different from hypothalamic/chiasmatic.

Hypothalamo-hypophysial dysfunction after traumatic brain injury in children and adolescents: a preliminary retrospective and prospective study.

With two study protocols, one retrospective and the other prospective, we evaluated hypothalamo-hypophysial dysfunction (HHD) in paediatric patients treated for traumatic brain injury (TBI) in the neurosurgical or intensive care department at our hospital. The retrospective group comprised 22 patients who had experienced TBI 0.7-7.25 years before the study. The prospective group included 30 patients assessed at TBI (T0), 26 of 30 after 6 months (T6), and 20 of 26 after 12 months (T12). Auxological and hormonal basal parameters of hypothalamo-hypophysial function were evaluated at recall in the retrospective group, and at T0, T6 and T12 in the prospective group. Basal data and standard dynamic tests in selected patients revealed one with precocious puberty, one with total anterior hypopituitarism, one with central hypogonadism, and one with growth hormone (GH) deficiency in the retrospective group; three patients with cerebral salt-wasting syndrome, one with diabetes insipidus and seven with low T3 syndrome at T0 (all transient), one with hypocorticism at T6 confirmed at T12, and one with GH deficiency at T12 in the prospective group. The results of our study show that post-TBI HHD in our paediatric cohort is not uncommon. Of the 48 patients who underwent a complete evaluation (22 retrospective study patients and 26 prospective study patients evaluated at T6) five (10.4%) developed HHD 6 months or more after TBI. HHD was newly diagnosed in one previously normal patient from the prospective group at 12 months after TBI. GH deficiency was the most frequent disorder in our paediatric cohort.

Cooperative study by the Italian neuroendoscopy group on the treatment of 61 colloid cysts.

OBJECTS: Microsurgical resection, stereotactic aspiration and VP shunt have for years been the choice options for the treatment of colloid cysts of the third ventricle. Recently, endoscopic approaches have aroused increasing interest and gained acceptance. Although safer, this minimally invasive approach is considered less efficacious than microsurgery. Relatively long-term results are now available and some conclusions might be inferred on the usefulness of this procedure. MATERIALS AND METHODS: Between 1994 and 2005, 61 patients harbouring a colloid cyst of the third ventricle were treated with neuroendoscopic technique in 11 Italian neurosurgical centres. Cyst diameters ranged from 6 to 32 mm. A flexible endoscope was used in 34 cases, a rigid one in 21, both instruments in six. The technique consisted in cyst fenestrations, colloid aspiration, coagulation of the internal cyst wall and, occasionally, capsule excision. Mean postoperative hospital stay was 6.7 days. Early postoperative neuroimaging revealed a cyst residue in 36 cases (mean diameter 4.3 mm). There were two complications (3.2%). Follow-up varied between 1 and 132 months (mean 32 months, more than 5 years in 17 patients). There were seven asymptomatic recurrences, three of them evolving from a previous residue. CONCLUSION: The endoscopic approach to the treatment of colloid cysts is safe, effective and well accepted by patients. Although asymptomatic, recurrences (11.4%) cast a persisting shadow on the long-term results, and, therefore, the controversy with the traditional microsurgical treatment remains open.

Diffuse and focal brain stem tumors in childhood: prognostic factors and surgical outcome. Experience in a single institution.

OBJECTIVE: Brainstem tumors (BSTs) are usually gliomas and are divided into diffuse BSTs (DBSTs) and focal BSTs (FBSTs). The aim of this study is to investigate the different outcomes of these two entities. METHODS: Thirty-one patients with BSTs were admitted to our institution from 1995 to 2003. Patients with DBSTs were treated with locoregional radiotherapy (1.8 Gy/day for 54 Gy) and weekly vincristine for radiosensitization (1.5 mg/sm for six total doses). Patients with FBSTs underwent surgical resection. Chemotherapy and/or radiotherapy were considered in progression. RESULTS AND CONCLUSIONS: Fourteen patients were diagnosed as having DBSTs. The responses to treatment were ten cases of partial response, three of stable disease, and one of progressive disease. General and/or neurological symptoms improved in more than 80% of patients. The median time from diagnosis to progression and to death were, nonetheless, 8 (range of 3-13) and 13 (range of 4-25) months, respectively, with a 2-year overall survival rate of 12.3% [standard error (SE) 11.2]. Seventeen patients were diagnosed as having FBSTs. Gross total removal was achieved in 4/17 cases, subtotal removal in 7/17, and partial removal in 6/17. There was one surgery-related death. Eight out of 17 patients had adjuvant chemo- and/or radiotherapy after progression: 6/8 are without neurological symptoms and 2/8 have died due to tumor progression. The 4-year overall and disease-free survival rates are 87.4 (SE 8.4) and 58.8% (SE 11.9), respectively, the extent of resection being the most important prognostic factor (p=0.012). DBSTs continue to carry a dismal prognosis, thus demanding new treatment modalities; FBSTs can be treated surgically and patients benefit from a better prognosis.

Endocrine function and water metabolism in children and adolescents with surgically treated intra/parasellar tumors.

Hydroelectrolytic disorders often complicate surgery of intra/parasellar tumors in children and adolescents. Eighteen patients undergoing microneurosurgical procedures for intra-supra-sellar craniopharyngioma (10 patients), hypothalamic germinomas (3 patients), hypothalamic-chiasmatic astrocytomas (3 patients), pituitary adenomas (2 patients) were studied. The hydroelectrolytic balance was assessed from 8 hours before surgery to 1 week after with a specific protocol in which water metabolism alterations were treated with standard procedure. Diabetes insipidus (DI) was observed in 10/18 patients before surgery and in 15/18 patients after surgery; during surgery it was effectively treated with synthetic desmopressin (DDAVP) and hydroelectrolytic solutions. Hyponatremia, isolated or associated (with diuresis contraction or polyuria), seen during surgery and in the following 24 hours, was treated with variation of the infusion rate. We show that close monitoring and treatment of hydroelectrolytic disorders in patients submitted to neurosurgery for intra/ parasellar tumors may significantly reduce their morbidity and mortality rate.

Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy.

PURPOSE: Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury. METHODS AND MATERIALS: The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n = 20 patients) vs. hyperfractionated radiotherapy (Group B, n = 12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET). RESULTS: The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p < 0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients. CONCLUSIONS: The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction.

Thyroid diseases in patients treated during pre-puberty for medulloblastoma with different radiotherapic protocols.

We evaluated thyroid disease in 32 patients treated, during pre-puberty, for medulloblastoma, followed for at least 4 years and without relapse during observation. After surgery the patients underwent chemotherapy (CT) and radiotherapy (RT). The protocols were as follows: 20 patients (group A) SNC 76 and SNC 85 protocols which included conventional fractionated RT (36-40 Gy to the craniospinal axis and a 14-18 Gy boost to the posterior fossa, administered as 1.5-1.8 Gy per fraction per day) and a junction between the cranial and the spinal fields at C2-C3 level; 12 patients (group B) SNC 91 protocol which included hyperfractionated RT (36 Gy to the craniospinal axis and a 30 Gy boost to the posterior fossa; this was administred as 1 Gy per fraction twice per day) and a junction at levels C5-C6 or C6-C7 level. The mean age at diagnosis was 7.4+/-3.2 years for group A and 8.4+/-2.6 years for group B. Thyroid function was evaluated yearly and ultrasonographic characteristics every 2 years. The patients were followed for a mean of 10.8+/-3.8 for group A and 6+/-1.4 years for group B. Primary hypothyroidism was diagnosed in 16 group A patients and 4 group B patients, and central hypothyroidism was diagnosed in 2 group A patients (difference in risk of developing hypothyroidism evaluated with a Wilcoxon-test: p=0.048). Ultrasonography showed reduced thyroid volume in 7 group A cases, and structural changes in 21 patients (17 group A, 4 group B); 9 L-thyroxine-treated patients were confirmed hypothyroid after having stopped therapy. A thyroid nodule was detected in two cases (one from each group). In conclusion, our data indicate that thyroid injury may be diminished by the use of hyperfractionation and low-junction radiotherapy in the treatment of medulloblastoma.

A patient with early puberty associated with Chiari 1 malformation.

A boy is described with early puberty and Chiari 1 malformation. It is not known whether there was an etiological relationship between these two conditions, or whether they were coincidental. This report emphasizes the utility of MRI when early puberty is diagnosed, particularly in males.

Macrocephaly-Cutis marmorata telangiectatica congenita without cutis marmorata?

We report on two patients with clinical manifestations consistent with a diagnosis of macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC). Both showed macrocephaly with high forehead, overgrowth, capillary hemangiomata involving philtrum, nose, and lips, and redundant skin. In addition, the first had cutis marmorata and joint laxity. The second had postaxial polydactyly of hands and feet, cutaneous syndactyly of third and fourth right fingers and of second and third right toes without evident cutis marmorata. A magnetic resonance imaging scan showed cerebral alterations in both patients. The first had bilateral cortical dysplasia with frontal bilateral myelinization defect of corona radiata. The second had mild intertonsillar widening, cavum septi pellucidi, small porencephalic areas in the anterolateral region of cellae, and subsequently developed a nonobstructive hydrocephalus. Reviewing all reported cases we propose a new criterion for M-CMTC diagnosis.

Chiari type I anomalies in children and adolescents: minimally invasive management in a series of 53 cases.

The authors studied the role of the sole posterior fossa bony decompression in the management of symptomatic children affected by Chiari type I anomalies. The series in the pediatric literature of this subject were reviewed and compared with that presented in this article. From May 1994 to December 1998, 53 patients (3 months to 26 years) were observed. They were divided into: asymptomatic patients (27), who received no surgical treatment and were only subject to clinical observation; symptomatic patients (brain stem compression 16, syringomyelia 10, including 7 with holocord). All the symptomatic patients were treated with the same surgical approach: bony decompression of posterior fossa with removal of the posterior arch of C-1 and the outer layer of the dura without dural opening. In all 16 (100%) of the 16 patients with brain stem compression the symptoms resolved or improved; in patients with syringomyelia the symptoms were resolved or improved in 94.4% of cases. Two children required further surgery after 13 and 24 months, respectively. This series seems to demonstrate that even a simple extradural surgical approach, with a lower rate of postoperative complications and short stay in hospital, is sufficient to arrest the disease and to improve the symptomatology in a high percentage of cases (97.2%), which is comparable to that achieved with other, more aggressive, procedures.

Long first metacarpal in monozygotic twins with probable Baller-Gerold syndrome.

We report on a pair of monozygotic twins with probable Baller-Gerold syndrome (BGS). Twin A had severe coronal craniosynostosis. Twin B had right radioulnar and ipsilateral first metacarpal hypoplasia. Both had bilateral fifth finger clinodactyly. Assuming that the twins were truly monozygotic, a single genetic disorder (i.e., BGS) could explain the variable expression. Together the twins have the typical anomalies of BGS. The diagnosis was supported by the metacarpophalangeal profile (MPP) which confirmed hypoplasia of the first right metacarpal in Twin A and bilateral fifth finger brachymesophalangy in both twins. Furthermore, the MPP showed an unexpected abnormal lengthening of the first metacarpal (unilateral in Twin A and bilateral in Twin B), a previously undetected radial ray defect in BGS. These findings suggest the possibility that the MPP may assist recognition of mild cases of BGS such as those with apparently isolated craniosynostosis or isolated upper limbs defects.

Ocular findings in children operated on for plagiocephaly and trigonocephaly.

Clinical examination of patients affected by plagiocephaly or trigonocephaly reveals evident malformation of the orbits, and the ocular repercussions are pronounced when children are operated on at an advanced age. Since it is generally accepted that binocular vision is fully developed by approximately 6 months of age, a late correction of plagiocephalic or trigonocephalic skull deformities may be an obstacle to the development of normal visual function. For the present report we investigated astigmatism and strabismus in 53 children, 39 of whom were operated on for plagiocephaly and 14 for trigonocephaly. Traction on the ocular globe induced by the bony deformation caused by the craniosynostosis may explain astigmatism and strabismus.

[Arachnoid cysts of the middle cranial fossa in children. A review of 75 cases, 47 of which have been operated in a comparative study between membranectomy with opening of cisterns and cystoperitoneal shunt]. / Les kystes arachnoïdiens temporo-sylviens chez l'enfant. Revue de 75 cas dont 47 ont été opérés et étude comparative entre la membranectomie avec ouverture des citernes et la dérivation kystopéritonéale.

The authors report their experience concerning 75 cases of middle fossa arachnoid cysts observed in children during the period 1975-1993, 47 of which (62.6%) were operated upon. The aim of this study was to study the clinical presentation of these cysts, to discuss the surgical indications and to compare the results of the various techniques used to treat these malformations. Head injury was revealing in 17 cases (22.6%) and among these, 12 patients presented intracranial complications (subdural effusions; 6 cases, subdural hematomas: 4 cases and intracystic hematomas: 2 cases). The most usual signs and symptoms were: intracranial hypertension (25.3%), epilepsy (16%) and temporal bulging (24%). Twenty-one patients (44.7%) underwent a cystoperitoneal shunt; 20 patients (42.5%) were treated by membranectomy with opening of the basal cisterns and removal of intracystic (2 cases) or subdural hematoma (4 cases); 2 patients (4.3%) were treated using membranectomy, opening of the cisterns and cystoperitoneal shunt and 4 patients (8.4%) underwent a subduroperitoneal shunt. The long-term results were good regardless of the surgical procedure; nevertheless, only one patient among 20 cases treated by membranectomy and opening of the cisterns developped complications (5%), while multiple shunt revisions were necessary in 11 children (40.7%) out of 27 where a shunt was inserted. The authors conclude that membranectomy and opening of the basal cisterns is the procedure of choice to treat middle fossa arachnoid cysts in children.

Supratentorial interhemispheric cysts associated with callosal agenesis: surgical treatment and outcome in 16 children.

Cerebrospinal-fluid-filled interhemispheric cysts associated with callosal agenesis are relatively rare lesions, and have been subject to a varied and confusing terminology. From a pragmatic surgical point of view, we believe that the dorsal III ventricular cyst [35] and the giant interhemispheric cyst [23], although of different embryological origin, can be classified as one group. The most important condition that must be distinguished from interhemispheric cysts is the alobar form of holoprosencephaly. We describe the clinical symptomatology in 16 children who were surgically treated with a cysto-peritoneal shunt. The outcome, both neurologically and developmentally, was good in the large majority of cases, and compared favorably to similar cases in the older literature. It therefore seems reasonable, at the present state of knowledge and until further studies clarify the origin and natural history of these cysts, to treat them as early as possible in order to prevent gross developmental deficits.

Ocular findings in trigonocephaly.

BACKGROUND: Trigonocephaly, caused by premature closure of the metopic suture, is a rare form of craniosynostosis. The aim of this study was to assess the visual outcome in children operated on for trigonocephaly. METHODS: We present eight cases of children with trigonocephaly surgically corrected by the same craniofacial technique. CT with 3D reconstruction was performed in all cases. Genitori defined three types of trigonocephaly according to the severity of the deformity of the skull base only types II and III were included in this study directed at evaluation of the ocular disorder. A complete eye examination was performed on all children by the same observer, with a follow-up of 2-6 years. RESULTS: 3D-CT reconstruction of the skull base showed that the frontozygomatic region was affected by the deformation. Ocular examination showed considerable astigmatism in most children with late operation. A low degree of strabismus was observed in most children. CONCLUSION: This study demonstrated that reconstructive surgery should be performed by the age of 6 months, given the immaturity of the visual system up to that time. Close cooperation between neurosurgeons, pediatricians and ophthalmologists is of paramount importance in order to prevent this bone deformation exerting an adverse effect on visual development. The ophthalmologist must possess a basic understanding of the various craniosynostoses.