Fossa In Children Research Articles

MRI evaluation of pediatric posterior fossa tumors and its correlation with histopathology: A prospective observational study

Background: The commonest malignancy in the pediatric age group is leukemia, followed by brain tumors. Pediatric brain tumors are usually seen in children below 10 years. The incidence ranges from 1 to 3 per 100,000 cases. Primary intracranial tumors most commonly occur in the posterior fossa in children while infratentorial tumors are predominant in children over 4 years. Infratentorial tumors are more common overall, accounting for 45-60% of all cases. Physiologic characteristics of the pediatric posterior fossa tumors are well represented in advanced MRI techniques, which results in better pre-operative tumor evaluation, and often better results. Objectives: Primary intracranial tumors most commonly occur in the posterior fossa in children. Treatment and prognosis rely heavily on correct diagnosis. The most important modality for early diagnosis is MRI of the brain. This study aims to evaluate the role of MRI in pediatric posterior fossa tumors. Materials and methods: Thirty-three patients in the pediatric age group (<18 years) with a clinical suspicion of posterior fossa tumors, referred to the department of Radiology for undergoing MRI of the brain with contrast were included in the study. These patients underwent surgery followed by histopathological examination (HPE). Five parameters from conventional MRI were chosen and correlated with histopathology (gold standard). Statistical analysis was done subsequently. Results: Diffusion-weighted imaging (DWI) is the most accurate parameter (94%), followed by T2 weighted imaging (T2WI), gradient, and post-contrast sequence (91% each). Diffusion-weighted imaging and post-contrast sequence had the highest specificity (almost 96%) while DWI and T2WI had the highest sensitivity (90% each). All 5 parameters are useful in 85% of cases. Overall diagnostic accuracy of MRI was almost 94% compared to histopathology. Conclusion: DWI is the best parameter, followed by T2WI, gradient imaging, and post-contrast sequence. MRI is highly accurate in the evaluation of pediatric posterior fossa tumors. In centers where advanced MRI techniques cannot be performed, some parameters from conventional MRI can be selected that aid in diagnosis. Our study shows that judicious use of 5 parameters can increase sensitivity, specificity, and diagnostic accuracy of MRI for pediatric posterior fossa tumors.

Noonan syndrome: Neuroimaging findings and morphometric analysis of the cranium base and posterior fossa in children.

There are a few studies regarding intracranial findings in neonates with Noonan syndrome (NS); however, there are no quantitative analyses in a pediatric population. The aim of this study was to find characteristic intracranial abnormalities and to quantitatively analyze the posterior fossa and cranium base in children with NS. A total of 30 patients (11 females and 19 males, mean age 13.1±4.3years) were retrospectively identified between July 2017 and June 2022. Twenty-one patients had MRI. Age at MRI examination, sex, genetic mutations, and clinical findings were noted. In patients with MRI, the presence of white matter lesions, basal ganglia lesions, corpus callosum abnormalities, sellar/parasellar lesions, and tonsillar ectopia was noted. For morphometric analysis, cerebellar diameter, vermis and clivus heights, cranial base, tentorial and infratentorial angles, and McRae's and Twining's lines were each measured twice by two radiologists individually. The most common lesions were focal white matter lesions, followed by abnormalities of the splenium of the corpus callosum. The cerebellar diameter, vermis and clivus heights, Twining's line, and infratentorial angle were significantly smaller; cranial base angle and tentorial angle were significantly larger in NS (p<.05). Interrater and intrarater agreements were the highest for cerebellar diameter and the lowest for tentorial angle measurements. Children with NS had characteristic callosal and tentorial findings and neuroimaging findings similar to other RASopathies. This study also shows that a small posterior fossa and flattening of the cranial base are present in children with NS, which may aid in diagnosis.

Age dependent prevalence of the supraacetabular fossa in children, adolescents and young adults

ObjectivesThe supraacetabular fossa (SAF) is an anatomical variant of the acetabular roof which may mimic a cartilage defect. Two different subtypes have been described: type 1 fluid-filled and type 2 cartilage-filled. The adult prevalence of SAF was reported between 10.5 and 12.6%. We aimed to determine SAF prevalence in a pediatric and young adult population and examine the potential remodeling of the subtypes over time.MethodsA retrospective search of the institutional database for hip MRI of participants aged 4–25 years was carried out between 2010 and 2020. A total of 401 eligible MRIs of 323 participants were analyzed by two readers. The documented features were: existence of SAF, definition of subtype and measurements of the SAF in three dimensions. Logistic regression models were calculated to estimate the influence of age on the presence of SAF.ResultsOut of 323, 115 (35,6%) participants demonstrated a supraacetabular fossa. 63 (19.5%) participants presented subtype 1 and 51 (15.8%) type 2; one participant had both. The predicted probability for SAF increases until the age of 14, beyond 14 years, the combined predicted probability for both subtypes decreased again. In contrast to SAF type 1, SAF type 2 was more prevalent with older age. The size of the SAF decreased with aging.ConclusionThe supraacetabular fossa is most frequent in adolescents. With higher age, the prevalence and the size of the SAF decreased. This data supports the theory that the SAF is a developmental variant.

Prevalence of Tumors in the Posterior Cerebral Fossa in Children and Adults, as well as their Histological Kinds: a Cross-Sectional Study

Aim: To determine the prevalence of posterior fossa tumors in children and adults, as well as their histological kinds. Study design: A cross-sectional study Place and duration: From February 2012 to January 2019, the Department of Neurosurgery at Riyadh Care Hospital Methodology: We undertook a descriptive analysis of patients with posterior fossa space-occupying lesions. The neurosurgical intervention was done in all of the instances due to the critical location. Specimens were sent for histological evaluation after surgery. The data from these patients, as well as histology reports, were examined. The data was analyzed using SPSS version 21. Results: Males made up 57.14 percent (n=48) of the 84 patients, while children made up 41.66 percent (n=35). The most common tumor was schwannoma, seen in 34.52 percent (n=29) of cases, 72.41 percent of adults, and 27.58 % of children. In 22.61 %, 15.47 %, and 14.28 % of cases, meningioma, pilocytic astrocytoma (PCA), and Meduloblastoma were found, respectively. Metastasis was only seen in adults, and malignant round blue cell tumors were only found in children. Astrocytoma and schwannoma were prevalent in adults. Children were more likely to develop Meduloblastoma, Pilocytic astrocytoma, and malignant round blue cell tumors. Conclusion: High-grade Astrocytoma and Schwannoma are dominantly present in adults. Malignant round blue cell tumor, Pilocytic astrocytoma Medulloblastoma is more prevalent in children. Metastasis was only observed in adults. Because of their location, risk of excision, and involvement of the brain stem structures and fourth ventricle, posterior fossa tumors are widely known for their significant morbidity and mortality. Early diagnosis is now possible due to modern diagnostic and therapy technologies, which help to lower mortality rates and improve postoperative prognosis. Keywords: posterior cerebral fossa tumors, children, adults

Infratemporal fossa synovial sarcoma in a 3-month-old infant: an extremely rare tumour in infancy

Soft tissue sarcoma, especially synovial sarcoma, is extremely rare in infancy, with only a few cases reported worldwide. Due to the particularly small size of the head and neck region in infants, with important anatomical structures in close vicinity to one another, surgical resection is very challenging, if the goal is to ensure total disease elimination as well as maintaining function and good cosmetic outcome postoperatively. In the case reported here, following diagnosis, the child was given three cycles of neoadjuvant chemotherapy followed by infratemporal tumour resection via Bramley–Al-Kayat incision incorporated with a modified Blair incision. Postoperatively, the child recovered well, with no recurrence after three months. This case highlights the important role of a multidisciplinary approach in the diagnosis and managing such rare cases. We also discuss the clinical presentation, imaging features, histopathological features, treatment regime, and prognosis of synovial sarcoma of the infratemporal fossa in children, based on cases reported in the literature.

Age-dependent differences of the depth of olfactory fossa in children

ObjectiveWith this radio-anatomical study, we aimed to describe the distribution of the depth of the olfactory fossa based on the Keros classification in the pediatric population in our region and to reduce complication rates by providing normative data. MethodsThis was a retrospective study conducted with computed tomography imaging of the paranasal sinuses of 390 pediatric patients referred over a six-year period in Sakarya and Kocaeli University Faculty of Medicine. Patients were divided into 3 groups as 1–6, 6–12, and 12–18 years old. The depth of the olfactory fossa was measured and classified according to the Keros classification. The incidence of Keros asymmetries was also investigated. ResultsThe distribution of the depth of a total of 780 olfactory fossa according to the Keros classification was 24.7% Keros I, 65.9% Keros II, and 9.4% Keros III. When the groups were evaluated with each other and within each group, it was seen that the prevalence of Keros I type was significantly higher in the first group (p<0.05), and the prevalence of Keros type II was significantly higher in the second and third groups (p<0.05). Apart from this, the number of Keros type III increased in the third group compared to the first two groups and showed a statistically significant difference (p<0.05). Among all patients, asymmetry of the olfactory fossa was detected in 29 patients (7.4%). Although the number of olfactory fossa asymmetry was low in group I, it was not significantly different between the groups (p>0.05). ConclusionIn our study, high Keros I rate and low Keros III rate in children aged 1–6 were remarkable. Especially for children under the age of six, questions arise about the validity of the Keros classification. More detailed studies in larger populations, in different ethnicities, and with various age groups are needed. Level of evidenceLevel 3.

Surgical approach to the posterior fossa in children, including anesthetic considerations and complications: The prone and the sitting position. Technical note

IntroductionMedulloblastoma (MB) in children is, in most cases, a midline lesion located in the posterior fossa, with a high tendency to invade the fourth ventricle (and sometimes its floor). MethodsIn this technical note, we present both the sitting and the prone position for children with medulloblastoma. These positions will be described together by deliberately deciding not to oppose one against the other. The park bench position, seldom used in pediatric neurosurgery is not described here. The latter procedure can be useful, however, for MB located more laterally or within the cerebellopontine angle. ResultsThe aim of this technical note is to provide the reader with a step by step procedure (from installation to closure), at least from the author's point of view. A special focus regarding anesthetic considerations is also provided. This anesthesia requires perfect coordination and communication between both the anesthetic and surgical teams. Complications of posterior fossa surgery are mentioned as well. Some of the advantages and disadvantages of each positions are mentioned. ConclusionOnly careful installation, respect of certain surgical principles (careful attention of the vermis and dentate nuclei for example), knowledge of anatomy, closure and perioperative monitoring, screening and immediate correction of potentially devastating complications will enable surgeons to obtain the best results from their surgery.

Effects of the growth pattern of medulloblastoma on short-term neurological impairments after surgery: results from the prospective multicenter HIT-SIOP PNET 4 study.

Extensive resection of a tumor in the posterior fossa in children is associated with the risk of neurological deficits. The objective of this study was to prospectively evaluate the short-term neurological morbidity in children after medulloblastoma surgery and relate this to the tumor's growth pattern and to the extent of resection. In 160 patients taking part in the HIT-SIOP PNET 4 (Hyperfractionated Versus Conventionally Fractionated Radiotherapy in Standard Risk Medulloblastoma) trial, neurosurgeons prospectively responded to questions concerning the growth pattern of the tumor they had resected. The extent of resection (gross, near, or subtotal) was evaluated using MRI. The patients' neurological status before resection and around 30 days after resection was recorded. Invasive tumor growth, defined as local invasion in the brain or meninges, cranial nerve, or major vessel, was reported in 58% of the patients. After surgery almost 70% of all patients were affected by one or several neurological impairments (e.g., impaired vision, impaired extraocular movements, and ataxia). However, this figure was very similar to the preoperative findings. Invasive tumor growth implied a significantly higher number of impairments after surgery (p = 0.03) and greater deterioration regarding extraocular movements (p = 0.012), facial weakness (p = 0.048), and ataxia in the arms (p = 0.014) and trunk (p = 0.025) compared with noninvasive tumor growth. This deterioration was not dependent on the extent of resection performed. Progression-free survival (PFS) at 5 years was 80% ± 4% and 76% ± 5% for patients with invasive and noninvasive tumor growth, respectively, with no difference in the 5-year PFS for extent of resection. Preoperative neurological impairments and invasive tumor growth were strong predictors of deterioration in short-term neurological outcome after medulloblastoma neurosurgery, whereas the extent of resection was not. Neither tumor invasiveness nor extent of resection influenced PFS. These findings support the continuation of maximal safe resection in medulloblastoma surgery where functional risks are not taken in areas with tumor invasion.

Primary Leptomeningeal Medulloblastoma: Desmoplastic/Nodular Medulloblastoma without a Discrete Parenchymal Mass

Medulloblastoma is one of the most common pediatric CNS malignancies and the most common primary tumor of the posterior fossa in children. Medulloblastoma can present with leptomeningeal seeding in up to 33% of patients at presentation. Primary leptomeningeal medulloblastoma without a discrete parenchymal mass has been reported 6 times in the literature to date, in both the pediatric and adult populations. This report aims to review the literature of these rare cases and present the first case of a primary leptomeningeal medulloblastoma with a desmoplastic/nodular subtype.

CLINICAL AND MORPHOLOGICAL JUSTIFICATION OF THE SURGICAL TREATMENT OF CHRONIC ABDOMINAL SYNDROME IN CHILDREN

The chronic recurrent abdominal syndrome (CRAS) in the right lower fossa in children is believed not to be independent nosological unit and is diagnosed as an exception. We carried out comparative studies of the clinical picture, results of morphological and immunohistochemical studies of remote appendicitis in 55 CRAS children and 35 children with acute destructive appendicitis. The low prognostic significance of appendicular scales for the determination of indications to the surgical treatment of CRAS was established. Morphological examination in most cases revealed signs of chronic inflammation with fibrosis of the mucosa and submucosa of the appendix in CRAS children. Immunohistochemical studies revealed the pronounced expression of protein VEGF, MMP-9 and VCAM-1 predominantly in the submucosal and the muscular layer, moderate expression for Collagen-III-alpha-1. The low number of positively stained cells for the VIP protein located both in the mucosa and in the submucosa. The number of MMP-9-positive cells was the largest, there was seen a moderate amount of VEGF, VIP and Collagen-III-alpha-1-positive cells. The disappearance of the abdominal syndrome after appendectomy was noted in 6% of CRAS patients. Recurrence of pain was observed in girls of pubertal age with the irregular menstrual cycle. The established changes in remote appendicitis, other than acute inflammation, make it possible to consider reasonable appendectomy as a way of treating CRAS in children.

Radicalness and complications of repeated surgery for malignant neuroepithelial tumors of the posterior cranial fossa in children

The study objective was to assess the resection extent of recurrent malignant neuroepithelial tumors of the PCF in children as well as the risk and structure of postoperative complications. The prospective study included 50 patients under the age of 18 who underwent surgery for recurrent malignant neuroepithelial tumors of the PCF at the Neurosurgical Institute (NSI) in the period between 2002 and June 2015. Anaplastic ependymomas were present in 37 patients, and medulloblastomas were detected in 13 patients. A total of 58 repeated surgeries were performed. GTR was achieved in 53 (91.4%) cases, near total resection (NTR) was achieved in 2 (3.4%) cases, and subtotal resection (STR) was achieved in 3 (5.2%) cases. The mean bed-day after surgery was 12 (4-47) days, and the mean critical care stay was 3.2 (0-23) days. Seven patients required tracheostomy; meningitis developed in 3 patients; liquorrhea occurred in 2 cases. Ventriculoperitoneal shunting was used in 8 (13.8%) cases. One (1.7%) patient died in the early postoperative period. Our results demonstrate that resection of recurrent malignant neuroepithelial tumors in children can be performed with high radicalness (90%) and acceptable risks.

P122 – 2666: Neuropsychological evaluation of children with middle cranial fossa arachnoid cysts, before and after decompression of the cyst through neurosurgical fenestration

Objective To evaluate cognitive outcome in children after surgical decompression of arachnoid cysts of the middle cranial fossa. An additional objective was to assess the children as one part of the decision whether to perform a surgical intervention or not. Arachnoid cysts are often considered asymptomatic incidental findings of MRI or CT. In this project the aim was to assess prevalence of cognitive symptoms correlated to the cyst and possible postsurgical improvement. Methods Neuropsychological assessment at the department of child neurology at Karolinska University Hospital, Stockholm. The assessment of intellectual ability was done using WISC-IV. Assessment of specific cognitive functions was done using NEPSY-II, Rey Oesterrieth Complex Figure test, BNT-II and FAS (test of verbal fluency). A follow-up with the same psychometric tests 4–5 months after surgery. Results To this date 6 children has gone through presurgical assessment. Four of six children showed cognitive symptoms in the assessment. Symptoms that was correlated to the location of the cyst and the neurosurgeon decided on fenestration of the cyst. Two of six children had no cognitive symptoms and the neurosurgeon decided on no surgical intervention. Two of the four children with symptoms have been evaluated 5 months after decompression of the cyst. Both clinical and psychometric results points towards reduction of cognitive symptoms in these two patients. Conclusion Neuropsychological assessment might be used as a help in decisions regarding surgery. Pre- and post-op assessment might be a way of evaluating the possible benefits of decompression of arachnoid cysts of the middle cranial fossa in children.

Recurring pain in right iliac fossa in children: report of two cases associated with food allergies

Cases Case # 1: Girl, 11, afflicts right lower quadrant pain for 3 months. Background Prematurity, atopy (dermatitis, rhinitis, colic). Sister and atopic mother. Physical examination: exquisite tenderness in the right iliac fossa, bilateral Cord colic pain. Dry skin. Laboratori data:all hematology is normal. Examination of normal urine, serial parasitological (-). EDN (eosinophil derived neurotoxin) fecal> 3210 ng / ml (VN <360NG / ml). Colonoscopy:ILNH, ileal lymphoid nodular hyperplasia. Food allergy Score: 9 Case No. 2: Boy, 9 years. Pain in right lower quadrant , abdominal pain for three months located in the right iliac fossa, a predominantly nocturnal and radiating to right thigh. A child psychiatrist prescribes antidepressants. Personal Background Mixed Breastfeeding from birth. Atopy: asthma, atopicdermatitis, infantcolic. Family history: Mother allergic to foods, presents father rhinitis. Physical examination: bilateral colic Rope. Tenderness in the right iliac fossa. Lab: Immunoglobulin E 160.5 IU / mL (normal <90) Colonoscopy lymphoid hyperplasia in distal ileum. Score of foodallergy: 11. Both cases improve with hypoallergenic diet.

V600E BRAF mutation in pilocytic astrocytoma is associated with a more diffuse growth pattern but does not confer a more aggressive clinical behavior.

Activation in mitogen activated protein kinase signaling pathway has recently been described as a predominant event in pilocytic astrocytoma (PA) and is commonly caused by constitutively active mutation in BRAF protein. Whereas PA of posterior fossa in children have a high prevalence of BRAF duplication and fusion, primary molecularm abnormalities in supratentorial tumors of adults are more diverse and also include BRAF V600E point mutation. In our study we evaluated 51 PAs for BRAF duplication and BRAF V600E point mutation. We found a relatively high frequency of V600E mutation in our cohort. Histologically, V600E-carrying PA appeared more infiltrative, yet our limited clinical follow-up failed to detect a deleterious prognostic significance.

Computed Tomographic Evaluation of Posterior Fossa Lesions

Background: Various neoplastic and nonneoplastic lesions can involve posterior cranial fossa. Posterior fossa lesions are potentially fatal since they may result in compression of the brainstem. The objective of this study was to analyze the spectrum of posterior fossa lesions and their clinical presentations. Methods: A prospective cross sectional study was conducted over a period of one year. Thirty patients with clinical features of posterior fossa pathology, referred for cranial computed tomography, were evaluated in the study. Results: Posterior fossa lesions found in this study were cerebellar abscess- 4(13.3%), arachnoid cyst- 4(13.3%), brainstem glioma- 3(10%), cerebellar astrocytoma- 3(10%), acute cerebellar infarct- 2(6.7%), cerebellar metastasis- 2(6.7%), acoustic neuroma- 2(6.7%), meningioma- 2(6.7%), medulloblastoma- 2(6.7%), ependymoma- 1(3.3%), Dandy-Walker malformation- 1(3.3%), 4th ventricular bleed- 1(3.3%), brainstem haemorrhage- 1(3.3%), cerebellar haemorrhage- 1(3.3%), and neurocysticercosis- 1(3.3%). The maximum numbers of cases (23.3%) with posterior fossa lesions were in their first decade of life. Features of raised intracranial pressure (i.e. headache, nausea &amp; vomiting) were the commonest presenting symptoms. Other symptoms included altered sensorium, ataxia, fever, limb weakness, vertigo, seizure, hearing loss, neck stiffness, slurring of voice, ear discharge, tinnitus, loss of consciousness and macrocrania in decreasing order of frequency. Conclusion: There is wide spectrum of the lesions in posterior fossa in children and adults in this part of Nepal, requiring prompt diagnosis and intervention, and CT has a pivotal role in the management. Nepalese Journal of Radiology / Vol.3 / No.1 / Issue 4 / Jan-June, 2013 / 53.58 DOI: http://dx.doi.org/10.3126/njr.v3i1.8796

Sigmoid colon in right iliac fossa in children

Sigmoid colon in right iliac fossa in children

Neuroimaging of pediatric posterior fossa tumors including review of the literature

Conventional, anatomical MRI is an essential tool for diagnosis and evaluation of location, quality, and extent of posterior fossa tumors, but offers limited information regarding tumor grade and type. Advanced MRI techniques such as diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) may improve the specific diagnosis of brain tumors in the posterior fossa in children. In this review the conventional neuroimaging findings, as well as the DWI, and DTI characteristics of common pediatric posterior fossa tumors are discussed and summarized.

Position of a sigmoid colon in right iliac fossa in children: A retrospective study

Aim:The aim was to identify the position of sigmoid colon in children and discuss its clinical significance.Materials and Methods:Ninety-one contrast enema studies were retrospectively evaluated and the position of sigmoid colon categorized as below: Left lower quadrant, right lower quadrant, midline, and indeterminate.Results:The position of sigmoid colon in the right lower quadrant, left lower quadrant, midline, and indeterminate was 32 (35.16%), 33 (36.26%), 12 (13.19%), and 14 (15.38%), respectively. There was no statistically significant difference in mean age (P = 0.87) or gender prevalence (P = 0.49) for different positions of the sigmoid colon.Conclusion:The sigmoid colon occupies the right lower quadrant in a large number of children. Awareness of this finding is of crucial importance in correct interpretation of abdominal radiographs in the emergency room.

Atypical teratoid/rhaboid tumour arising in association with a pleomorphic xanthoastrocytoma: a case report

Atypical teratoid rhabdoid tumour (AT/RT) is a rare, highly malignant embryonal tumour most often occurring in the posterior fossa in children under 3 years of age. We report a case of a supratentorial AT/RT arising in association with a pleomorphic xanthoastrocytoma (PXA). A 6-year-old girl presented with a 1 month history of headache and vomiting. An MRI showed a heterogeneously enhancing mass involving the posterior left frontal lobe associated with marked local mass effect. Following a subtotal resection of the tumour she commenced treatment with chemoradiation. Histological sections showed a tumour with two distinct but focally intermixed morphological appearances, a high grade component with cellular morphology typical of an AT/RT and a low grade component with features of a PXA. The diagnosis was confirmed by demonstrating immunohistochemical loss of INI1 expression, restricted to the rhabdoid areas. In addition, a significantly higher proportion of the rhabdoid cells showed loss of a chromosome 22 marker by fluorescent in situ hybridisation. To our knowledge this is the second reported case of an atypical teratoid rhabdoid tumour arising in the setting of a pleomorphic xanthoastrocytoma. We postulate that the AT/RT arose through secondary genetic events in the PXA, including INI1 inactivation.

Dimensions and Ossification of the Normal Anterior Cranial Fossa in Children

Interpretation of CT of the anterior skull base in children depends on knowledge of the pattern and chronology of ossification. The purpose of this study was to ascertain the age at which the anterior cranial fossa is fully ossified as assessed on CT examinations. This was a retrospective review of 127 CT examinations of children ranging from 1 day to 16 years 7 months of age without known or suspected anterior cranial fossa abnormality. Measurements of the length and width of the anterior skull base and the presence and size of the most anterior unossified portion were determined by 2 investigators. At birth, the anterior skull base consists mainly of cartilage. There is a wide variation in ossification rates between individuals, but the anterior skull base was fully ossified at 3 years 10 months in all of our cases. In healthy individuals, the anterior skull base is fully ossified by 4 years of age.