Posterior Fossa Medulloblastoma Research Articles

Etiology- and region-specific characteristics of transependymal cerebrospinal fluid flow.

Transependymal flow (TEF) of CSF, often delineated as T2-weighted hyperintensity adjacent to the lateral ventricles on MRI, is a known imaging finding, usually in the setting of CSF flow disturbances. Specific radiological features of TEF and their relationships with clinical markers of hydrocephalus and underlying disease pathology are not known. Here, the authors describe the radiological features and clinical associations of TEF with implications for CSF circulation in the setting of intracranial pathology. After obtaining IRB review and approval, the authors reviewed the radiological records of all patients who underwent intracranial imaging with CT or MRI at St. Louis Children's Hospital, St. Louis, Missouri, between 2008 and 2019 to identify individuals with TEF. Then, under direct review of imaging, TEF pattern, degree, and location and underlying pathology and other radiological and clinical features pertaining to CSF circulation and CSF disturbances were noted. TEF of CSF was identified in 219 patients and was most prevalent in the setting of neoplasms (72%). In 69% of the overall cohort, TEF was seen adjacent to the anterior aspect of the frontal horns and the posterior aspect of the occipital horns of the lateral ventricles, and nearly half of these patients also had TEF dorsal to the third ventricle near the splenium of the corpus callosum. This pattern was independently associated with posterior fossa medulloblastoma when compared with pilocytic astrocytoma (OR 4.75, 95% CI 1.43-18.53, p = 0.0157). Patients with congenital or neonatal-onset hydrocephalus accounted for 13% of patients and were more likely to have TEF circumferentially around the ventricles without the fronto-occipital distribution. Patients who ultimately required permanent CSF diversion surgery were more likely to have the circumferential TEF pattern, a smaller degree of TEF, and a lack of papilledema at the time of CSF diversion surgery. CSF transmigration across the ependyma is usually restricted to specific periventricular regions and is etiology specific. Certain radiological TEF characteristics are associated with tumor pathology and may reflect impaired or preserved ependymal fluid handling and global CSF circulation. These findings have implications for TEF as a disease-specific marker and in understanding CSF handling within the brain.

Adult medulloblastoma: a case report

BackgroundMedulloblastoma is a malignant brain tumor that is common in children but very uncommon in adults, especially those older than 40 years, accounting for less than 1% of all primary brain tumors in adults. Although surgery and radiotherapy play an important role treatment of adult medulloblastoma, the use of chemotherapy is controversial. This is the first instance of adult medulloblastoma at the Ocean Road Cancer Institute in Tanzania.Case descriptionWe report the case of a 51-year-old female of African ethnicity who was diagnosed with high-risk hemispheric posterior cranial fossa medulloblastoma of classic type with World Health Organization central nervous system grade 4 and Chang stage M0. Immunohistochemistry, reticulin stain, and molecular subtyping could not be done because they were not available. She was treated by subtotal posterior cranial fossa tumor resection followed by adjuvant concurrent chemo-craniospinal radiation and adjuvant chemotherapy.ConclusionEven in adults over 50 years old, medulloblastoma should be included in the differential diagnosis of posterior fossa tumor. Adult medulloblastoma is a very rare and very heterogeneous tumor, but it has a good prognosis. Immunohistochemistry and molecular subclustering are difficult to implement in low-income countries such as Tanzania owing to cost. Treatment of adult medulloblastoma is highly heterogeneous among (and even within) facilities. There is no evidence that the extent of resection enhances survival. While craniospinal radiation therapy improves survival, there is controversy about the role of chemotherapy in managing adult MB.

Post ventriculoperitoneal shunting S. Maltophilia Meningitis

Background: Leptomeningeal inflammation caused by S. Maltophilia is rare. It is inextricably linked with prior antimicrobial therapy, prolonged ICU stays and antecedent neurosurgical intervention. Case description: We describe a case of a 5-year-old male child with posterior fossa medulloblastoma with obstructive hydrocephalus who underwent ventriculoperitoneal shunt followed by suboccipital midline craniotomy and later presented with S. Maltophilia meningitis. Conclusion: The overall mortality in the cases reviewed was 17 per cent. Inherent resistance to a wide array of antimicrobial agents with a simultaneously increasing number of cases poses a therapeutic challenge. Trimethoprim/sulfamethoxazole is recommended as empirical and as a definitive treatment in patients with S. Maltophilia infection. The optimal duration of therapy for S. Maltophilia meningitis is similar to the treatment of gram-negative bacillary meningitis, which is usually 2 weeks after the culture has been negative.

Predictive Factors for Postoperative Tracheostomy Requirement in Children Undergoing Surgical Resection of Medulloblastoma

This study is aimed at identifying factors predicting tracheostomy requirement in children diagnosed with a posterior fossa medulloblastoma postoperatively. A retrospective chart review of all patients younger than 18 undergoing medulloblastoma resection from 2012 to 2020 at Namazi Hospital was conducted. Forty-five patients (26%) needed tracheostomy after the operation. The most common correlates were brainstem compression and absence of gag reflex before operation. Patients who had brainstem compression and infiltration by medulloblastoma, bilateral absence of gag reflex before operation, subtotal resection of the tumor, and postoperative brainstem contusion were more likely to require tracheostomy. No statistically significant difference was observed between males and females and different ages. Medulloblastoma is the most common pediatric malignancy. Postoperative ventilator dependency is an important complication in postoperative recovery of patients undergoing medulloblastoma resection. Considering the mutism syndrome with all its question marks by means of predisposing factors, we dealt with a 2-week policy whether there would be any clinical resolution regarding patients' gag reflex. The results show that if we aim for total tumor resection, tracheostomy that is a highly costly and stressful postoperative morbidity can be prevented.

Pediatric Posterior Fossa Medulloblastoma: The Role of Diffusion Imaging in Identifying Molecular Groups.

The molecular groups WNT activated (WNT), Sonic hedgehog activated (SHH), group 3, and group 4 are biologically and clinically distinct forms of medulloblastoma. We evaluated apparent diffusion coefficient (ADC) values' utility in differentiating/predicting medulloblastoma groups at the initial diagnostic imaging evaluation and prior to surgery. We retrospectively measured the ADC values of the enhancing, solid portion of the tumor (EST) and of the whole tumor (WT) and performed Kruskal-Wallis testing to compare the absolute tumor ADC values and cerebellar and thalamic ratios of three medulloblastoma groups (WNT, SHH, and group 3/group 4 combined). Ninety-three children (65 males) were included. Fifty-seven children had group 3/group 4, 27 had SHH, and 9 had WNT medulloblastomas. The median absolute ADC values in the EST and WT were .719×10-3 and .864×10-3 mm2 /s for group 3/group 4; .660×10-3 and .965×10-3 mm2 /s for SHH; and .594×10-3 and .728×10-3 mm2 /s for WNT medulloblastomas (P = .02 and .13). The median ratio of ADC values in the EST or the WT to normal cerebellar tissue was highest for group 3/group 4 and lowest for WNT medulloblastomas (P = .03 and .09), with similar results in pairwise comparisons of the corresponding thalamic ADC values (P = .02 and .06). ADC analysis of a tumor's contrast-enhancing solid portion may aid preoperative molecular classification/prediction of pediatric medulloblastomas and may facilitate optimal surgical treatment planning, reducing surgery-induced morbidity.

Long-term outcome of posterior fossa medulloblastoma in patients surviving more than 20 years following primary treatment in childhood

The aim of the study was to analyze the long-term outcome (>20 years) after treatment of posterior fossa medulloblastoma (MB) in childhood. We analyzed data from patients treated for posterior fossa MB between 1974 (introduction of the first international treatment protocol in Norway) and 1987 (when use of radiotherapy was abandoned in children under 4 years of age). Out of 47 children, 24 survived >20 years. At the time of analysis, 16 patients (median age 41 years, range 32–52) were alive (median follow-up 34 years, range 30–42), while 8 patients died 22–41 years (median 31 years) after primary treatment: one late death (after 22 years) was due to tumor recurrence whilst other 7 deaths (after 23 to 41 years) were related to the detrimental effects of the treatment (secondary tumors, stroke, severe epilepsy and depression). Observed 20- and 30-year survival rates were 51% and 44%, respectively. Despite successful treatment of MB in childhood and satisfactory tumor control during the first 20 years following primary treatment, our data indicates that even long-term survivors may die from tumor recurrence. However, the main factors causing late mortality and morbidity in long-term survivors seem to be the complications related to radiotherapy given in childhood.

P.095 Novel use of fluorescein sodium in the resection of a pediatric posterior fossa tumor

Background: Gross total resection of pediatric posterior fossa tumors is paramount towards improving progression-free survival.Fluorescein accumulates in tumoral tissue, where the blood-brain barrier is disrupted. It can therefore potentially aid in differentiating tumoral versus normal tissue. We aimed to evaluate the efficacy of fluorescent-guidance (using fluorescein) towards the resection of a pediatric cerebellar tumor, as the index case at our institution using this technique. Methods: 5 mg/kg of IV fluorescein sodium was injected upon induction of general anesthesia. During tumor resection, a yellow 560-nm filter (Kinevo microscope, Zeiss) was employed for fluorescent-guidance. The extent of resection was assessed via post-operative MRI. Results: There were no adverse side effects experienced by the patient. Tumoral material was clearly visualized under the yellow 560-nm filter, allowing for satisfactory gross total resection of the lesion (confirmed on post-operative MRI). Preliminary pathology was consistent with medulloblastoma. Conclusions: Fluorescent-guided resection of pediatric posterior fossa tumors appears to be a safe and useful adjunct for gross total resection of these lesions. To the best of our knowledge, this is the first reported case in Canada wherein IV fluorescein was used under a yellow 560-nm filter for resection of a posterior fossa medulloblastoma in a child.

Thoracic medulloblastoma metastasis

Introduction: Medulloblastoma is one of the most frequent malignancies of Central Nervous System (CNS) in childhood and has low incidence in adult population. Recurrences are frequent in both populations; systemic metastasis is a rare event. Objective: Report an unusual medulloblastoma case evolution, with thorax metastasis after 6 years of quiescence and compare results with literature data. Methods: Registers survey of previously operated patient from a posterior fossa medulloblastoma with diagnose of thoracic metastasis. Acquired data were analyzed and compared with those from literature. Case report: Twenty-two years-old patient, with a previously operated on posterior fossa medulloblastoma . Six years later, presents with asthenia and vertigo: an x-ray diagnosis of a lesion in the apex of left chest is confirmed with a thoracic computerized tomography. A laparoscopic biopsy is done, disclosing an infiltrative tumor, adherent to the parietal pleura and highly vascularized. AP diagnosis was compatible with metastasis of medulloblastoma. Conclusion: Posterior fossa recurrences are frequent in the adult population, followed by the subfrontal region. About 5% of meduloblastoma metastases are systemic, especially in bones (77%), and even rarer in the lungs, as shown in this report.

Apraxia of speech and cerebellar mutism syndrome: a case report

BackgroundCerebellar mutism syndrome (CMS) or posterior fossa syndrome (PFS) consists of a constellation of neuropsychiatric, neuropsychological and neurogenic speech and language deficits. It is most commonly observed in children after posterior fossa tumor surgery. The most prominent feature of CMS is mutism, which generally starts after a few days after the operation, has a limited duration and is typically followed by motor speech deficits. However, the core speech disorder subserving CMS is still unclear.Case presentationThis study investigates the speech and language symptoms following posterior fossa medulloblastoma surgery in a 12-year-old right-handed boy. An extensive battery of formal speech (DIAS = Diagnostic Instrument Apraxia of Speech) and language tests were administered during a follow-up of 6 weeks after surgery. Although the neurological and neuropsychological (affective, cognitive) symptoms of this patient are consistent with Schmahmann’s syndrome, the speech and language symptoms were markedly different from what is typically described in the literature. In-depth analyses of speech production revealed features consistent with a diagnosis of apraxia of speech (AoS) while ataxic dysarthria was completely absent. In addition, language assessments showed genuine aphasic deficits as reflected by distorted language production and perception, wordfinding difficulties, grammatical disturbances and verbal fluency deficits.ConclusionTo the best of our knowledge this case might be the first example that clearly demonstrates that a higher level motor planning disorder (apraxia) may be the origin of disrupted speech in CMS. In addition, identification of non-motor linguistic disturbances during follow-up add to the view that the cerebellum not only plays a crucial role in the planning and execution of speech but also in linguistic processing. Whether the cerebellum has a direct or indirect role in motor speech planning needs to be further investigated.

Papillary carcinoma thyroid as a second malignant neoplasm following radiotherapy for medulloblastoma in childhood: A rare case report

Second malignant neoplasm is a rare but dreaded late sequelae of the treated primary childhood malignancies. Surgical excision combined with radiochemotherapy represents the gold standard of therapy for medulloblastoma. The effectiveness of such a combined treatment has encouraged the use of radiotherapy even in young pediatric patients, in spite of the increased risk of a second radio-induced malignancy. Irradiation is the well-known risk factor for the development of benign and malignant thyroid tumors. Children are more exposed to this risk because their thyroid gland is more sensitive to the carcinogenic effect of ionizing radiation. We report the case of a 20-year-old male who initially presented at the age of 2 years with a medulloblastoma and was treated with surgery and radiotherapy. The patient again presented 18 years after radiotherapy with bilateral neck masses which proved to be lymphadenopathy secondary to papillary carcinoma of the thyroid. The patient also had multiple bilateral metastatic pulmonary nodules. Radio-induced thyroid tumors are well-recognized nosographic entities due to the particular sensitivity of this gland to ionizing radiations. However, only a few papers on radio-induced thyroid neoplasms after the central nervous system (CNS) irradiation have been published in the literature. We report an additional case of thyroid neoplasm following childhood CNS irradiation for the treatment of posterior fossa medulloblastoma and emphasize that clinicians should judiciously use the radiotherapy for treatment of childhood malignancies and also radiologists should be familiar with the long-term complications of antineoplastic therapies to facilitate early diagnosis and treatment.

Teaching Neuro Images : Postoperative bifocal stroke of the pontine tegmentum

A 7-year-old boy underwent resection of a posterior fossa medulloblastoma. Two days later, he developed facial diplegia, left abducens nerve palsy, and mild hypalgesia below the neck. MRI documented 2 dot-like ischemic foci in the pons (figure). We diagnosed the unusual bilateral occurrence of Gasperini syndrome, a lesion of the sixth and seventh cranial nerve nuclei and the lateral spinothalamic tract that produces ipsilateral cranial nerve palsies with contralateral hemisensory deficits.1 We hypothesized a mechanism of postoperative spasm of long circumferential branches of the basilar artery. This mechanism should be considered in cases of postoperative neurologic deficits with delayed onset.2

Hypertrophic olivary degeneration with gadolinium enhancement after posterior fossa surgery in a child with medulloblastoma

Hypertrophic olivary degeneration (HOD) is a rare transsynaptic form of degeneration occurring secondary to the disruption of the dentato-rubro-olivary pathway ("Guillain-Mollaret triangle"). HOD can be caused by ischemic, hemorrhagic, traumatic, or neoplastic lesions, and it can also occur following posterior fossa surgery. MRI characteristics of HOD include T2 signal increase and hypertrophy. To date, blood–brain barrier disruption has not been reported in HOD. Here, we present the first case of HOD with temporary gadolinium enhancement in a 10-year-old child 7 months after resection of a posterior fossa medulloblastoma. The recognition of gadolinium enhancement as a radiological feature of HOD may help to distinguish between this benign secondary condition and tumor recurrence.

Spinal subdural hematoma following posterior fossa surgery

Summary Spinal subdural hematoma (SSDH) is a rare but potentially devastating complication of cranial surgery. This study presents two cases of SSDH after posterior fossa surgery. The first case was a 44-year-old man who harbored a fourth ventricle metastatic adenocarcinoma, and the second case was a 4-year-old boy with a posterior fossa medulloblastoma. Both patients underwent suboccipital craniotomy, and SSDHs were found postoperatively. The first case underwent an additional lumbar laminectomy due to cauda equina syndrome; the second case received conservative treatment because there were no obvious neurologic deficits. Meticulous hemostasis and the avoidance of cerebrospinal fluid overdrainage may reduce the risk of SSDH after cranial surgery. Emergent decompression is warranted for SSDH in the presence of progressive neurologic deterioration.

Symptomatic Cerebral Vasospasm Following Resection of a Medulloblastoma in a Child

Vasospasm may occur following intracranial tumor resection but is uncommon following resection of tumors in the posterior fossa. Case report. Here, we report an unusual pediatric case of symptomatic cerebral vasospasm following resection of a posterior fossa medulloblastoma in a 10-year-old child. CT angiogram and serial Transcranial Doppler (TCD) studies confirmed the presence of vasospasm and response to hemodynamic augmentation therapy, resulting in favorable outcome. This case illustrates an unusual complication of posterior fossa tumor resection, and the potential utility of TCD studies in the detection and management of vasospasm in pediatric neurocritical care.

Urethral protrusion of the abdominal catheter of ventriculoperitoneal shunt: Case report of extremely rare complication

Hydrocephalus in its various forms constitutes one of the major problems in pediatric neurosurgical practice. The placement of a ventriculoperitoneal (VP) shunt is the most common form of treatment for hydrocephalus, so that all neurosurgeons struggle with shunt malfunctions and their complications. Well-known complications are connected with the use of the valve systems (malfunction, infectious, overdrainage, secondary craniosynostosis, etc.). We report an unusual case of protruding abdominal catheter from the urethra. This girl had received a VP shunt for hydrocephalus following surgery of posterior fossa medulloblastoma 4 years ago. After admission, the entire system was removed, antibiotic treatment was administered for 2 weeks, and a new VP shunt was placed. The postoperative course was uneventful. This complication is extremely rare.

A case report on successful pregnancy and delivery in a medulloblastoma patient

수질아세포종(medulloblastoma)은 성인에게 매우 드문 질환이다. 치료는 수술적 제거와 방사선 조사가 병행되며, 두개척수 조사 후 시상하부-뇌하수체축과 자궁, 난소의 손상으로 불임을 유발할 수 있어 임신 가능성이 매우 낮다. 저자들은 수질아세포종으로 뇌수술 및 전뇌 척추 방사선 조사 치료 후에도 자연 임신하였던 환자를 경험하였다. 산모는 임신 26주에 두통과 허리통증의 발생을 동반한 수질아세포종의 재발 및 척추 전이를 진단 받았으나 임신을 지속하기 위해 보존적 치료를 유지하던 중 반복되는 전신 경련 증상으로 임신 29주 3일에 제왕절개 분만하였고, 신생아의 경과가 양호하여 건강하게 퇴원하였다.

Preoperative and postoperative neurological, neuropsychological and behavioral impairment in children with posterior cranial fossa astrocytomas and medulloblastomas: the role of the tumor and the impact of the surgical treatment

The aim of the present study was to prospectively investigate if a correlation might exist between preoperative and postoperative neurological conditions, neuroradiological/intraoperative findings and results of a complete neuropsychological evaluation in children with posterior fossa medulloblastomas and astrocytomas. Of the 65 children admitted at the Pediatric Neurosurgery of the UCSC of Rome between January 2005 and October 2009, 41 were selected; the only two exclusion criteria were represented by age under 24 months and severe neurological conditions, seen that in both cases it would not have been a possible reliable evaluation. All children underwent a preoperative and immediate postoperative complete MR study. Hydrocephalus was graded on the Evans score; brainstem infiltration was defined on intraoperative findings. Neuropsychological assessment consisted of a battery of tests tailored on the patient's age, cognitive level, and level of cooperation. Post operative neuropsychological evaluation was performed at a mean time of 2.5 min (2 mos, max 4.5 mos) from the operation, before any eventually needed adjuvant treatment (i.e., chemotherapy, radiotherapy). Concerning neurological status, we found a statistically significant relation between the presence of oculomotor impairment and both verbal fluency deficits (p = 0.044) and imagery disorders (p = 0.03); also, the presence of ataxia/dysmetria was significantly correlated to attention dysfunction (p = 0.01) and, more tightly, to planning dysfunction (p = 0.006). For neuroradiological/intraoperative features, Intelligence Quotient (IQ) impairment was significantly correlated to the intraoperative evidence of tumor infiltration of the brainstem (p = 0.003), a severe hydrocephalus at diagnosis (p = 0.001) and the histological diagnosis of medulloblastoma (MB) (p = 0.002). For selective skills, a significant correlation was found between linguistic processing deficits and the evidence of dentate nuclei infiltration (blindly defined on MR); procedural memory defects and imagery disorders related to the severity of the hydrocephalus (p = 0.02), infiltration of the brain stem (p = 0.01) and a histological diagnosis of MB (p = 0.01). After surgery no patient showed a worsening of his/her cognitive profile; the relationships between clinical, intraoperative, and radiological findings were substantially confirmed. Our results support the hypothesis that when present, neuropsychological impairment is already present at diagnosis and that the most statistically significant factors, which might be related with cognitive deficits in the preoperative as well as in the postoperative period, are tumor infiltration of the brainstem, the severity of hydrocephalus, and a histological diagnosis of MB.

Symptomatic syringomyelia occurring as a late complication of posterior fossa medulloblastoma removal in infancy in a boy also suffering from scaphocephaly

The association of a medulloblastoma and a syringomyelia has been already described in rare instances albeit without symptoms related to the syrinx. The case of a 23-year-old man operated in infancy for a medulloblastoma and then treated solely with adjuvant chemotherapy is reported. He was also operated in infancy for a scaphocephaly. With a very long time delay, he has developed a Chiari I and a symptomatic cervico-dorsal syringomyelia. The symptoms attributed to the syrinx consisted of a unilateral prurigo over the left arm which was so severe to lead to self-mutilation. Clinical and magnetic resonance imaging follow-up after cervico-dorsal decompression shows a significant improvement of the symptoms together with a reduction of the size of the syrinx. This case is discussed in the light of the presumed pathophysiology of the syrinx and its exceptional clinical presentation.

Thyroid neoplasm after central nervous system irradiation for medulloblastoma in childhood: report of two cases

Surgical excision combined with radio-chemotherapy represents the gold standard of therapy of medulloblastoma. The effectiveness of such a combined treatment has encouraged the use of radiotherapy even in young paediatric patients, in spite of the many adverse effects reported in literature, and, in particular, the increased risk of a second radioinduced malignancy. Irradiation is the well-known risk factor for development of benign and malignant thyroid tumours. Children are more exposed to this risk because of their thyroid gland is more sensitive to carcinogenic effect of ionising radiation. Two children underwent radiotherapy for the treatment of a medulloblastoma when they were 3 and 4 years old, respectively. At the age of 20 and 23, both of them underwent the surgical excision of a papillary thyroid carcinoma, 20 and 17 years after the radiotherapeutic treatment, respectively. Radioinduced thyroid tumours are a well-recognised nosographic entities due to the particular sensitivity of this gland to ionising radiations. However, only a few papers on radioinduced thyroid neoplasms after CNS irradiation have been published in the literature. We report on two additional cases of thyroid neoplasms following childhood CNS irradiation for the treatment of a posterior fossa medulloblastoma.

Bilateral extradural hematoma formation following excision of a thoracic intradural lesion

The authors report an unusual case of a 15-year-old girl who previously underwent resection of a posterior fossa medulloblastoma, and later underwent resection of a thoracic extramedullary metastatic lesion. Her consciousness deteriorated hours after removal of her spinal metastasis. A CT head scan identified bilateral extradural cranial hematomas, which were evacuated. To the authors' knowledge, this is the first report of a patient developing bilateral acute cranial extradural hematomas following excision of a thoracic intradural lesion.