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Pilocytic astrocytoma (PAs) represents a significant portion of childhood primary brain tumors, with distinct histological and radiological features. The prevalence of KIAA1549::BRAF fusion in PAs has been well-established, this study aims to assess the prevalence of KIAA1549::BRAF fusions and explore their associations with tumor characteristics, radiological findings, and patient outcomes in PAs. Histologically confirmed cases of PAs from a 5-year period were included in the study. Demographic, histopathological, and radiological data were collected, and immunohistochemistry was performed to characterize tumor markers. FISH and qRT-PCR assays were employed to detect KIAA1549::BRAF fusions. Statistical analyses were conducted to examine associations between fusion status and various other parameters. Histological analysis revealed no significant differences in tumor features based on fusion status. However, younger age groups showed higher fusion prevalence. Radiologically, fusion-positive cases were distributed across different tumor subtypes SE, CWE and NCWE. Survival analysis did not demonstrate a significant impact of fusion status on overall survival, however most cases with recurrence and death harboured KIAA1549::BRAF fusion. Of 200 PAs, KIAA1549::BRAF fusions were detected in 64 % and 74 % of cases via qRT-PCR and FISH, respectively. Concordance between the two platforms was substantial (86 %). KIAA1549::BRAF fusions are prevalent in PAs and can be reliably detected using both FISH and qRT-PCR assays. Cost considerations suggest qRT-PCR as a more economical option for fusion detection in routine clinical practice. • The study examined KIAA1549-BRAF fusions in 200 cases and association with tumor features, radiology and patient outcomes • No significant tumor feature differences observed based on fusion status; higher prevalence in younger age groups. • Radiological features of NCWE and SE found dominantly associated with fusion-positive cases. • qRT-PCR and FISH detected fusions in 64% and 74% of cases,with 86% concordance and their pros and cons were discussed. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare the diagnostic value and accuracy of ictal SPECT and inter-ictal magnetoencephalography (MEG) in localizing the site for surgery in persons with drug resistant epilepsy.Method: This was a prospective observational study. Patients expected to undergo epilepsy surgery were enrolled consecutively and the localization results from different imaging modalities were discussed in an epilepsy surgery meet. Odds ratio of good outcome (Engel I) were calculated in patients who underwent surgery in concordance with MEG and SPECT findings. Post-surgical seizure freedom lasting at least 36 months or more was considered the gold standard for determining the diagnostic output of SPECT and MEG.Results: MEG and SPECT were performed in 101 and 57 patients respectively. In 45 patients SPECT could not be done due to delay in injection or technical factors. The accuracy of MEG and SPECT in localizing the epileptogenic zone was found to be 74.26 % and 78.57 % respectively. The diagnostic odds ratio for Engel I surgical outcome was reported as 2.43 and 5.0 for MEG and SPECT respectively. The diagnostic odds ratio for MEG in whom SPECT was non-informative was found to be 6.57 [95 % CI 1.1, 39.24], although it was not significantly associated with good surgical outcome. MEG was useful in indicating sites for SEEG implantation.Conclusion: SPECT was found to be non-informative for most patients, but reported better diagnostic output than MEG. MEG may be a useful alternative for patients in whom SPECT cannot be done or was non-localizing. [ABSTRACT FROM AUTHOR]

Malignant neuroectodermal tumor of infancy is a rare neural crest cell-derived neoplasm of infants. Histologically, melanotic neuroectodermal tumor of infancy usually consists of 2 types of cells: neuroblast-like and melanocyte-like cells. Here we present a rare case of melanotic neuroectodermal tumor of infancy containing a third type of cell population, that is, rhabdomyoblasts in addition to the above two. We report a case of a 10-month-old female child who was brought to us with complaints of swelling over the right forehead for the last 9 months, which started increasing in size rapidly 3 months before presenting to us. Noncontrast computed tomography scan showed a large well-defined extra-axial lesion in the right frontotemporal region. The child underwent an open biopsy under general anesthesia. Histopathological sections showed a malignant small round cell tumor consisting of hyperchromatic cells lying in sheets and lobules separated by fibrous septae. The patient underwent 7 cycles of neoadjuvant chemotherapy over a period of 2 months. The patient underwent right frontotemporal craniotomy and gross total excision of the lesion as a definitive surgery. Postoperatively, the patient was stable, and there was no new deficit. Histopathology revealed neuroblast-like and melanocyte-like cells with rhabdomyosarcomatous differentiation. The patient received chemotherapy in the postoperative period. The patient had recurrence of the tumor and died 8 months after the surgery. Calvarial malignant neuroectodermal tumor of infancy with rhabdomyosarcomatous differentiation is a rare entity with no cases being reported before. Neoadjuvant chemotherapy with surgical excision can be a promising modality of treatment. [ABSTRACT FROM AUTHOR]

Till date there are no randomized trials to suggest the superiority of intra-operative magnetic resonance imaging (IOMRI) guided trans-sphenoidal pituitary resection over two dimensional fluoroscopic (2D-F) guided resections. We conducted this trial to establish the superiority of IOMRI in pituitary surgery. Primary objective was to compare extent of tumor resection between the two study arms. It was a prospective, randomized, outcome assessor and statistician blinded, two arm ( A: IOMRI, n = 25 and B: 2D-F, n = 25 ), parallel group clinical trial. 4 patients from IOMRI group cross-over to 2D-F group and were consequently analyzed in latter group, based on modified intent to treat method. A total of 50 patients were enrolled till completion of trial ( n = 25 in each study arm). Demographic profile and baseline parameters were comparable among the two arms ( p > 0.05) except for higher number of endoscopic procedures and experienced neurosurgeons (>10 years) in arm B ( p = 0.02, 0.002 respectively). Extent of resection was similar in both study arms ( A, 94.9% vs B, 93.6%; p = 0.78 ), despite adjusting for experience of operating surgeon and use of microscope/endoscope for surgical resection . We observed that use of IOMRI helped optimize the extent of resection in 5/20 patients (25%) for pituitary tumor resection in-group A. Present study failed to observe superiorty of IOMRI over conventional 2D-F guided resection in pituitary macroadenoma surgery. By use of this technology, younger surgeons could validate their results intra-operatively and hence could increase EOR without causing any increase in complications. [ABSTRACT FROM AUTHOR]

Purpose: To determine if ictal-magnetoencephalography (ictal-MEG) source localization (SL) added information towards delineating the ictal-onset zone (IOZ), whether and how it helped final decision-making in epilepsy-surgery.Methods: Definite focal clusters on ictal-MEG were available for 32 DRE-patients, data was analyzed (single equivalent current dipole (ECD) model), SL done. Clinical history, long-term video-EEG (VEEG) monitoring, epilepsy-protocol MRI, FDG-PET, ictal-SPECT and interictal-MEG were discussed at the multispeciality Epilepsy Surgery Case-conference (ESC). Cases were reviewed with ictal-MEG SL presented only at the last ESC (after decision using other available modalities). Patients were grouped as VEEG localization and MRI-lesion concordant (Group-A), discordant (Group-B), and no MRI-lesion (Group-C). Final hypothesis or decision, surgical outcome in those operated, and how ictal-MEG data influenced them were recorded.Results: Five lesion-negative patients had identification of lesions after review of MRI with ictal-MEG SL. The difference between numbers of patients cleared for surgery without and with ictal MEG data was statistically significant (p=0.0044); but the difference in those cleared for phase II monitoring was not (p=1.00). Ictal MEG influenced decisions on possibility of surgery in 9 and converted decisions of phase II monitoring in 11 patients to electrocorticography-guided lesionectomy (20 in all; Group A-11, Group B-4, Group C-5); five were operated, with good seizure-control on follow-up.Conclusions: Delineation of IOZ by ictal-MEG helped convert DRE patients unsuitable for surgery or planned for phase II monitoring into candidates suitable for surgery, even ECoG-guided resections, and resulted in favorable outcomes in those who were operated. [ABSTRACT FROM AUTHOR]

Purpose: Ictal motor phenomena play a crucial role in the localization of seizure focus in the management of refractory focal epilepsy. While the importance of unilateral automatisms is well established, little attention is paid to the contralateral relatively immobile limb. In cases where automatisms mimic clonic or dystonic movements and in the absence of previously well-established signs, unilateral relative ictal immobility (RII) is potentially useful as a lateralizing sign. This study was carried out to examine the lateralizing value of this sign and to define its characteristics among patients of refractory focal epilepsy.Methods: VEEGs of 69 consecutive patients of refractory focal epilepsy who had undergone epilepsy surgery at our center over last four years were reviewed and analyzed for the presence of RII. Unilateral RII was defined as a paucity of movement in one limb lasting for at least 10s while the contralateral limb showed purposive or semi-purposive movements (in the absence of tonic or dystonic posturing or clonic movements in the involved limb). The findings were seen in the light of VEEG, radiological and nuclear imaging data, and with post-surgical outcome.Results: Unilateral RII as a lateralizing sign was found in 24 of 69 patients (34.78%), consisting of both temporal and extra temporal epilepsy, with 100% concordance with VEEG and MRI data. All patients demonstrating this sign had a good post-surgical outcome.Conclusion: RII, when well characterized is a frequent and reliable lateralizing sign in patients of refractory focal epilepsy. [ABSTRACT FROM AUTHOR]

We report our initial experience to optimize neurosurgical procedures using high field strength intraoperative magnetic resonance imaging (IOMRI) in 300 consecutive patients as high field strength IOMRI rapidly becomes the standard of care for neurosurgical procedures. Three sequential groups (groups A, B, C; n = 100 each) were compared with respect to time management, complications and technical difficulties to assess improvement in these parameters with experience. We observed a reduction in the number of technical difficulties ( p < 0.001), time to induction ( p < 0.001) and total anesthesia time ( p = 0.007) in sequential groups. IOMRI was performed for neuronavigation guidance (n = 252) and intraoperative validation of extent of resection (EOR; n = 67). Performing IOMRI increased the EOR over and beyond the primary surgical attempt in 20.5% (29/141) and 18% (11/61) of patients undergoing glioma and pituitary surgery, respectively. Overall, EOR improved in 59.7% of patients undergoing IOMRI (40/67). Intraoperative tractography and real time navigation using re-uploaded IOMRI images (accounting for brain shift) helps in intraoperative planning to reduce complications. IOMRI is an asset to neurosurgeons, helping to augment the EOR, especially in glioma and pituitary surgery, with no significant increase in morbidity to the patient. [ABSTRACT FROM AUTHOR]

Abstract: Alveolar soft part sarcoma (ASPS) is a relatively rare tumor that mostly presents as a slow growing mass in the deep soft tissue of the extremities. A substantial number of cases in children occur in the head and neck region; however, in any age group, it is very rarely reported in the sinonasal region. We report a case of ASPS of the paranasal sinuses with sellar extension in a 25-year-old man that masqueraded as a giant invasive pituitary adenoma. This is only the fifth case of sinonasal ASPS in literature. The clinical and radiological diagnoses were misleading, but an extensive pathology workup including electron microscopy helped reach an accurate diagnosis in this unusual case. [Copyright &y& Elsevier]

Abstract: Epithelial-myoepithelial carcinoma is a rare tumor of the salivary gland constituting only 1% of all tumors. It is a low-grade malignancy characterized by a classical biphasic morphology and immunophenotype. In the lacrimal gland, it is extremely rare with only 3 cases reported in the English medical literature. We describe the fourth case of epithelial-myoepithelial carcinoma, the first case in a female patient, and review the available literature. [Copyright &y& Elsevier]

Abstract: Primary spontaneous cerebrospinal fluid (CSF) rhinorrhea is rare. Only two such cases with a defect in the clivus have been previously reported in the world literature. The purpose of this report is not to discuss the operative approach or results but the etiopathogenesis of the defect at this very rare site. One patient had a defect in the posterior wall of the sphenoid sinus, just caudal to the dorsum sellae. In the other, a psuedomeningocele (thickened arachnoid outpouching) was found protruding into the sphenoid sinus through a defect in the middle of the clivus. Both cases were successfully managed with transsphenoidal surgery. Two additional cases of primary spontaneous CSF rhinorrhea through a defect in clivus are reported. The possible mechanism of the fistulae are discussed. [Copyright &y& Elsevier]

Abstract: Background: Deposition of CPPD crystals occurs in the fibrous and hyaline cartilage of the joints and intervertebral disks of the spine. Half of patients known to have chondrocalcinosis had asymptomatic calcification in the odontoid region. The cases of 12 patients with a spinal cord syndrome secondary to CPPD deposition in the odontoid region were published in the literature. In all those cases, the mass lesion was extradural in location with good outcome after surgical decompression via the transoral route. Case Description: We report on a rare case of large periodontoid CPPD deposition causing cervicomedullary compression, erosion of the overlying bone, and underlying dura with intradural extension and vertebral artery encasement. Conclusions: Calcium pyrophosphate dihydrate is a rare cause of cervicomedullary compression. Intradural extension of periodontoid CPPD has not been reported on. [Copyright &y& Elsevier]

Abstract: Ewing''s sarcomas (ES) account for approximately 10% of primary malignant bone tumors. Primary Ewing''s sarcoma of the skull is a very rare entity. We report a case of Ewing''s sarcoma of the sphenoid bone in a 5-year-old boy. CT scan showed heterogeneously enhancing mass with associated spiculated new bone formation along the posterolateral wall of the orbit. Magnetic resonance (MR) imaging showed markedly heterogeneously signal intensity mass lesion containing areas of hemorrhage and fluid–fluid levels. Spiculated new bone formation and fluid–fluid levels had not been reported previously in skull Ewing''s sarcomas and may be helpful features for preoperative diagnosis. [Copyright &y& Elsevier]

Endonasal endoscopic transsphenoidal surgery (TSS) and resection of pituitary adenomas are considered the gold standard treatment for Cushing disease (CD). Even with various recent advances in management, disease persistence and recurrence are common in these patients. The remission rate in the global population after surgery has been reported to vary widely from 64% to 93%. This study aims to determine the various clinical, biochemical, radiological, and histological factors that correlate with persistence and recurrence in patients with CD. This study also aims to understand the clinicopathological significance of EGFR-MAPK, NF-κB, and SHH pathway activation and to study the protein expression of activation markers of these pathways (i.e., c-Fos, c-Jun, GLI-1, pMEK, NR4A1, and p44) in functioning corticotroph pituitary adenomas. From January 2009 to September 2022, the clinical data of 167 patients who underwent surgical treatment (n = 174 surgeries) for CD with a median follow-up of 8.1 years (range, 1–13.29 years) were ambispectively analyzed. The preoperative clinical, biochemical, and radiological features, operative findings, postoperative clinical and biochemical data, and histopathological and molecular profiles were retrieved from the electronic medical records. The patients were followed up to assess their remission status. Among the 174 surgeries performed, 140 were primary surgeries, 22 were revision surgeries, 24 surgeries were for pediatric patients, and 12 surgeries were for patients with Nelson syndrome. In the primary surgery cohort, 74.3% were female, and the average age was 28.73 ± 10.15 years. Of the primary surgery cohort, 75% of the patients experienced remission compared with 47.4% after revision surgery. The remission rate for the pediatric patients was 55.5%. The postoperative day 1 plasma cortisol (P < 0.001; area under the curve, 0.8894; range, 0.8087–0.9701) and adrenocorticotropic hormone (P < 0.001; area under the curve, 0.9; range, 0.7386–1) levels were seen to be strong independent predictors of remission in the primary surgery cohort. The remission rate after endoscopic TSS was greater than that after microscopic TSS in patients undergoing primary surgery (81.08% vs. 57.14%; P = 0.008). The presence of adenoma on histopathological examination (HPE) was also a strong predictor of disease remission (P = 0.020). On stratifying by surgical approach and HPE, microscopically operated patients without histopathological evidence of adenoma had significantly higher odds of nonremission (odds ratio, 38.1; 95% confidence interval, 4.2–348.3) compared with endoscopically operated patients with adenoma found on HPE. A lower immunoreactivity score for NR4A1 was found to correlate with higher remission rates (P = 0.074). However, none of the molecular markers studied (i.e., c-Fos, c-Jun, GLI-1, pMEK, and p44) showed a significant correlation with the preoperative cortisol values. The remission rate after primary surgery is higher than that after revision surgery and is lower for pediatric patients than for adults. The postoperative day 1 plasma cortisol and adrenocorticotropic hormone levels are strong independent predictors of remission in the primary surgery cohort. An endoscopic approach with histopathological evidence of adenoma is associated with a higher remission rate; thus, endoscopy should be the approach of choice for these patients with the goal of identification of an adenoma on HPE. [ABSTRACT FROM AUTHOR]

Abstract: Pineal anlage tumour is a rare tumour of the pineal gland that is not listed in the 2007 World Health Organization classification of tumours of the central nervous system. Pineal anlage has been defined as a primary pineal tumour with both neuroepithelial and ectomesenchymal differentiation but without endodermal differentiation. We report a pineal anlage tumour in a 4-month-old boy, the youngest patient reported with this rare tumour, with a brief review of the literature. Clinicians and neuropathologists should be aware of this entity as it is likely to be misdiagnosed as a teratoma or a melanocytic tumour of the central nervous system. [Copyright &y& Elsevier]

Abstract: Hypoglossia-hypodactyly syndrome is characterised by small tongue associated with limb deficiency. It is an extremely rare condition with around 30 cases reported in world literature. We report a case of hypoglossia-hypodactyly syndrome that in addition to features already described also had supernumerary nipples, microcephaly and micropenis with cryptorchidism. Hypodactyly was symmetrical in all four limbs. These features have not been reported previously. [Copyright &y& Elsevier]

Summary: Foreign bodies are rarely encountered in nasopharynx. Two cases of unusual foreign bodies in nasopharynx are reported. One patient had bobbin (metallic thread roller used in sewing machine) and other one presented with a safety pin. Diagnosis was confirmed by radiological examination. Bobbin was retrieved whereas safety pin was swallowed by the patient. The details are hereby discussed. [Copyright &y& Elsevier]

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Background and Objectives: Ischemic stroke (IS) and coronary artery disease (CAD) share common risk factors and one may be the harbinger of the other. We aimed to study prevalence of symptomatic and asymptomatic CAD in a cohort of consecutive patients with IS and assess its relationship with intracranial and extracranial large artery cerebrovascular disease (LAD).Methods: All consecutive eligible IS and Transient Ischemic Attack (TIA) patients were recruited into the study. Both clinically suspected and asymptomatic patients (N = 259) underwent myocardial Stress-rest Gated Technetium-99m (Tc99m) MIBI Myocardial Perfusion SPECT scan performed on a dual head SPECT-CT to estimate evidence of myocardial ischemia.Results: Three hundred patients completed the study. Forty one patients were previously diagnosed cases of definitive CAD. Twelve patients were clinically suspected to have CAD and 247 patients were asymptomatic. Among these, 12 patients (4.81%) had a positive SPECT. The overall prevalence of CAD was 17.67% (n = 53). Presence of diabetes was an independent predictor of CAD (OR 1.98, 95% CI 1.07-3.67. P .02). No significant association was found between the presence of LAD and CAD in all subgroup comparisons. However, there was a suggestion of higher LAD among patients with known CAD compared with others.Conclusions: CAD is prevalent in patients with ischemic stroke. No definitive relationship was found between CAD and intracranial or extracranial LAD. Population based stratification tools are needed to further assess the need to detect subclinical CAD in patients with stroke. [ABSTRACT FROM AUTHOR]

Neurocysticercosis (NCC) is the commonest parasitic infection of the central nervous system. There is significant difference in incidence of NCC depending on geographic location, and incidence as high as 4% is reported in the endemic areas. It results from human affliction by the larval stage of Taenia solium. Spinal NCC is quite rare as compared with cranial NCC and accounts for 1.5%–3% of all cases. Both spine and cranium can be rarely involved in NCC, and cranial involvement usually precedes the spinal involvement. We report a case of a 51-year-old woman who had spinal involvement first in the form of spinal intradural extramedullary disease and then developed cranial involvement more than 1 year later. She developed spinal arachnoiditis. She developed communicating hydrocephalous requiring ventriculoperitoneal shunt. Later she developed isolated fourth ventricle and required excision of the fourth ventricular NCC. The unique aspects of our patient were a very aggressive course and involvement of cranium after spinal involvement. We describe her clinical course over 3 years and the management done. NCC can sometimes follow a very aggressive course and can involve both cranial and spinal compartments. Management of such patients is not standardized given the rarity of such cases. [ABSTRACT FROM AUTHOR]

Moyamoya disease (MMD) is characterized by supraclinoid internal carotid artery narrowing causing cerebral parenchyma to starve. Direct and indirect revascularisation techniques are the treatment norm. We provide a clinicoradiological comparison of single and double barrel superficial temporal artery to middle cerebral artery (STA-MCA) bypass for MMD. The perfusion in cerebral hemispheres and vessel density in digital subtraction angiography (DSA) have been evaluated using novel algorithms. DSA, arterial spin labeling magnetic resonance imaging methods and Suzuki, Matsushima, Angiographic Outcome Score scales were used to quantify perfusion parameters; modified Rankin Score was used for clinical evaluation. A novel image processing algorithm was designed to perform analysis of arterial spin labeling sequences and compare perfusion. Vessel density was calculated using connected component analysis on thresholded DSA images. Fifty-four hemispheres with MMD underwent STA-MCA bypass 42(77.8%) single barrel and 12 (22.2%) double barrel. Clinical outcome—modified Rankin Score was significant with P < 0.001 in single barrel and P = 0.001 in double barrel groups. The overall Angiographic Outcome Score showed improvement postoperatively (P = 0.032). Perfusion analysis was performed in 20 hemispheres (13 single barrel; 7 double barrel). MCA territories showed significant improvement in single barrel (2.72%, P = 0.0294) and double barrel groups (12.89%, P = 0.025). Vessel density calculated in MCA territory, showed an overall postoperative improvement (P = 1.75 × 10–8). Double barrel STA-MCA bypass clinically as well as radiologically improves perfusion in the ACA as well as MCA territories in MMD. The novel image processing algorithm is an accurate, objective tool to evaluate perfusion in magnetic resonance images and vessel density in DSA images of MMD. [ABSTRACT FROM AUTHOR]

Too little is known about DMJD in adults. Various phenotypic presentations in adults with DMJD and long-term follow-up is needed to further characterise this disease. [ABSTRACT FROM AUTHOR]

Background Thalamopeduncular gliomas arise at the junction of the thalamus and cerebral peduncle and constitute a subgroup of thalamic gliomas. These are surgically challenging lesions because of close proximity to important neural structures including corticospinal tracts (CSTs) and the thalamus. These tumors usually displace CSTs anterolaterally or extend to the lateral ventricular surface. Such tumors can be removed by either temporal or transventricular approaches. However, if CSTs cover the entire lateral surface of tumor and tumor does not extend to the ventricular surface, temporal and transventricular approaches cannot be used because the trajectories of both approaches would pass through normal eloquent structures (CSTs and thalamus), and consequently there would be a very high risk of postoperative neurologic deficits developing. Case Description A 50-year-old woman presented with contralateral hemiparesis. Radiologic evaluation revealed a right Thalamopeduncular glioma that displaced CSTs laterally and was covered by normal thalamus superiorly. Some CST fibers passed through the tumor. Because both lateral and superior surfaces were covered by eloquent structures, we used an anterior interhemispheric transparaterminal gyrus approach to access the tumor successfully and achieved subtotal excision. The patient had transient neurologic deterioration postoperatively that recovered to preoperative level within 2 weeks. Conclusions The anterior interhemispheric transparaterminal gyrus approach has not been described previously for accessing brainstem lesions. This approach can be used to access tumors of the cerebral peduncle that displace CSTs laterally and are covered by normal thalamus superiorly. The anterior interhemispheric transparaterminal gyrus approach adds to the armamentarium of neurosurgeons for treatment of cerebral peduncular lesions. [ABSTRACT FROM AUTHOR]

Subependymal giant cell astrocytoma (SEGA) is a World Health Organization grade 1 neoplasm, which, due to its dubious morphologic features, may be misdiagnosed as a high-grade tumor at times. This tumor shows binary immunoexpression including both glial and neural markers, leading to a state of diagnostic quandary. Recent evidences have surmised the diagnostic utility of thyroid transcription factor 1 (TTF-1), spurring us to study the practicality of this marker in distinguishing SEGAs from its mimics. In this study, TTF-1 immunohistochemistry using clone 8G7G3/1 (1:50) was performed in 38 cases of SEGA, 30 cases of central neurocytoma, 10 cases each of intraventricular glioblastoma and ependymoma, and 5 cases of cortical tubers. Additionally, serine/threonine-protein kinase B-Raf (BRAFV600E) mutation, a common genetic alteration in pediatric low-grade-glial tumors with neuronal-differentiation, was analyzed using Ventana immunohistochemistry platform. TTF-1 immunopositivity was seen in all 38 cases (100%) of SEGAs, with 20 cases (52.6%) showing diffuse (>50% of tumor area) expression while focal (<50%) immunopositivity was seen in 18 cases (47.3%). None of the cases demonstrated serine/threonine-protein kinase B-Raf immunolabeling. Barring 2 cases of neurocytoma (6.6%), all other cases including ependymoma, glioblastoma, and cortical tubers were immunonegative for TTF-1. The congruous finding of TTF-1 expression in SEGA and cells of the developing neuroepithelium in the medial ganglionic eminence hint toward a primogenitor cell with neoplastic potential in the presence of impelling factors. [ABSTRACT FROM AUTHOR]

Cervical pedicle screws (CPS) in the subaxial cervical spine (C3-C6) are faced with high incidence of perforating the lateral pedicular cortex endangering the vertebral artery (VA). The present study analyzes the pedicle width (PW) from C3 to C6 and defines the relation of VA with regard to pedicle and transverse foramen (TF) to determine the safety margin in cases of lateral pedicular breach. Computed tomography angiograms of 500 patients were retrospectively studied to identify the pedicle width (PW), VA area, TF area, and the lateral pedicle to vertebral artery distance (LPVA). Occupancy ratio (OR; the percentage area of transverse foramen occupied by VA) and safety margin (SM; permissible displacement of VA in TF), along with LPVA were considered to be protective parameters against VA injury if lateral pedicle breach happens. PW was 4.7 mm at C3, 4.83 mm at C4, 5.26 mm at C5 and 5.41 mm at C6. Mean LPVA at different levels was between 0.97 mm and 1.15 mm, OR was around 20% at all levels, and mean SM was between 2.34 mm and 2.92 at various levels. Sex differences were statistically significant for PW but not for LPVA, SM, or OR. This study gives us an idea about the various parameters in placement of cervical pedicle screw in subaxial cervical spine and the probable reasons there are few vertebral artery injuries despite high incidence of cervical pedicle breach. LPVA, safety margin, and OR may explain why even very significant CPS misplacement does not lead to vascular injury or neurologic deficit. [ABSTRACT FROM AUTHOR]