A pediatric cerebral tumor with MN1 alteration and pathological features mimicking carcinoma metastasis: may the terminology "high grade neuroepithelial tumor with MN1 alteration" still be relevant?

INTRODUCTION

Astroblastoma, MN1-altered (old name: high-grade neuroepithelial tumor/HGNET with MN1 alteration) is a recently described central nervous system tumor mostly affecting pediatric patients and profoundly young girls. Differential pathological diagnoses of these tumors include ependymoma, pleomorphic xanthoastrocytoma, embryonal tumor with multilayered rosettes, meningioma, and even glioblastoma. As the treatment approaches to these tumors differ, it is essential to increase the awareness about these tumors in the neurosurgical community.

CLINICAL PRESENTATION

A 7-year-old female patient admitted with a 7-day history of headache, nausea, and vomiting. A contrasted MRI scan revealed a left parietal 4 × 4 × 5 cm mass with central necrosis and peripheral contrast enhancement. The tumor's histopathological findings were suggestive of a metastatic carcinoma with unknown primary, yet further genetic analysis revealed MN1 alteration. Peculiarly, the tumor pathomorphological features were not compatible with astroblastomas and exerted features strongly indicating a metastatic cancer; however, systemic PET and whole-body MRI failed to detect a primary malignancy.

OUTCOME AND CONCLUSIONS

Eighteen months after gross-total tumor resection, an in-field and out-field multifocal recurrence developed which required a second surgery and subsequent chemo-radiotherapy. The patient is doing well for 1 year after the second treatment regimen at the time of this report. Despite the final cIMPACT6 classification in 2020 advised to define all MN1 altered brain tumors as astroblastomas, there exist prognostic differences in MN1-altered tumors with and without morphological features of astroblastoma. Rare morphological variants of MN1-altered tumors shall be recognized for their future prognostic and clinical classification. HGNET with MN1 alteration seems still be a more proper definition of such malignancies as an umbrella term.

Treatment Strategies for Dopamine Agonist-Resistant and Aggressive Prolactinomas: A Comprehensive Analysis of the Literature

Despite most of the prolactinomas can be treated with endocrine therapy and/or surgery, a significant percentage of these tumors can be resistant to endocrine treatments and/or recur with prominent invasion into the surrounding anatomical structures. Hence, clinical, pathological, and molecular definitions of aggressive prolactinomas are important to guide for classical and novel treatment modalities. In this review, we aimed to define molecular endocrinological features of dopamine agonist-resistant and aggressive prolactinomas for designing future multimodality treatments. Besides surgery, temozolomide chemotherapy and radiotherapy, peptide receptor radionuclide therapy, estrogen pathway modulators, progesterone antagonists or agonists, mTOR/akt inhibitors, pasireotide, gefitinib/lapatinib, everolimus, and metformin are tested in preclinical models, anecdotal cases, and in small case series. Moreover, chorionic gonadotropin, gonadotropin releasing hormone, TGFβ and PRDM2 may seem like possible future targets for managing aggressive prolactinomas. Lastly, we discussed our management of a unique prolactinoma case by asking which tumors' proliferative index (Ki67) increased from 5-6% to 26% in two subsequent surgeries performed in a 2-year period, exerted massive invasive growth, and secreted huge levels of prolactin leading up to levels of 1 605 671 ng/dl in blood.

Neurosurgical and neuro-immunological management of IgG4-related hypertrophic sclerosing pachymeningitis. A literature survey and discussion of a unique index case

BACKGROUND

Dural thickening is observed in lymphoma, dural carcinomatosis, meningioma, tuberculosis, and autoimmune diseases. We encountered a patient with dural thickening and complaints of neck and back pain, numbness and loss of strength in the hands. The patient also suffered from polychondritis and had previously received steroid and methotrexate treatment for this indication. The patients' serum was also positive for ANA, yet she did not have any other findings suggesting lupus. Our radiological and pathological analysis revealed IHSP (IgG4-related hypertrophic sclerosing pachymeningitis). In this review study, we provided a detailed literature survey to increase the awareness about IHSP in the neurosurgical community.

METHODS

MRI (magnetic resonance imaging)-based radiological analyses revealed a posterior extramedullary spinal mass extending from C2 to T2-T3 level. The dural mass was surgically excised and a broad panel of immunohistochemical markers including S100, EMA, CD246/ALK-1, CD45, CD20, CD79a, CD138, CD68, CD1a and CD34 was studied. Immunoglobulin heavy chain/kappa chain gene rearrangement analysis was performed which ruled out a lymphoproliferative disorder.

RESULTS

MRI and pathological findings suggested IHSP. As the disease relapsed with a new anterior extramedullary multilobulated lesion extending from C5 to T1 level, the patient is now closely monitored for further medical and surgical treatment.

CONCLUSIONS

IHSP is a relatively novel entity of hypertrophic pachymeningitis and should be included in the differential diagnosis of dural thickening. The fibrosis accompanying IHSP may not respond to medical treatment, which includes steroids and immunosuppressive agents. Additionally, neurological deficits, seizures, spinal decompression, hydrocephalus, or brainstem compression necessitate early surgical intervention. A continued vigilance is also necessary as the disease may relapse long-term following surgical treatment.

Long non-coding RNA MALAT1 as a key target in pathogenesis of glioblastoma. Janus faces or Achilles' heal?

Glioblastomas (GBMs) are primary brain tumors with extremely bad prognosis and therefore; discovery of novel regulators of their pathology is of immense importance. LncRNAs (long noncoding RNAs) regulate nuclear structure, embryonic pluripotency, cell differentiation, development and carcinogenesis. Many lncRNAs have weak evolutionary conservation; however, a nuclear lncRNA, MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), is exceptionally conserved and is among the most abundant lncRNAs in benign tissues. The majority of cell culture studies and clinico-epidemiological studies demonstrated that MALAT1 acts a tumor promoter in GBMs and inhibition of MALAT1 suppressed tumor growth in various preclinical models of GBM. MALAT1 involves in stemness of GBM cells by regulating SOX2, nestin and members of WNT pathway. MALAT1 induces protective autophagy and suppresses apoptosis in GBM cells via sponging miRNA-101 and increases temozolomide chemoresistance via enhancing epithelial-mesenchymal transition, suppressing miR-203 and promoting thymidilate synthase. Moreover, knockdown of MALAT1 expression enhances blood-brain tumor barrier permeability via miR-140, which may provide a double benefit of MALAT1 suppression by increasing the delivery of chemotherapy agents into the GBM tissues. On the other hand, there also exist some cell culture and animal studies showing that MALAT1 acts as a tumor suppressor in GBMs by suppression of ERK/MAPK and MMP2 signaling and by repression of miR-155 with subsequent increase of FBXW7. Whether protective or detrimental, MALAT1 seems to be an important component of GBM pathogenesis and hence; novels studies are needed in versatile models, including many different primary GBM cultures, orthotopic and xenogreft in vivo models and transgenic mice.

Methylnitrosourea, dimethylbenzanthracene and benzoapyrene differentially affect redox pathways, apoptosis and immunity in zebrafish

Cancer continues to be a major cause of mortality globally. Zebrafish present suitable models for studying the mechanisms of genotoxic carcinogens. The aim of this study was to investigate the interaction between oxidant-antioxidant status, apoptosis and immunity in zebrafish that were exposed to three different genotoxic carcinogens methylnitrosourea, dimethylbenzanthracene, benzoapyrene and methylnitrosourea + dimethylbenzanthracene starting from early embryogenesis for 30 days. Lipid peroxidation, nitric oxide levels, superoxide dismutase and glutathione-S-transferase activities and mRNA levels of apoptosis genes p53, bax, casp3a, casp2 and immunity genes fas, tnfα and ifnγ1 were evaluated. The disruption of the oxidant-antioxidant balance accompanied by altered expressions of apoptotic and immunity related genes were observed in different levels according to the carcinogen applied. Noteworthy, ifnγ expressions decreased in all carcinogen-exposed groups. Our results will provide basic data for further carcinogenesis research in zebrafish models.

Neuroprotective effects of mitoquinone and oleandrin on Parkinson's disease model in zebrafish

Aim: The aim of this study is to investigate the possible protective effects of mitoquinone and oleandrin on rotenone induced Parkinson's disease in zebrafish. Materials and methods: Adult zebrafish were exposed to rotenone and mitoquinone for 30 days. Biochemical parameters were determined by spectrophotometric method and Parkinson's disease-related gene expressions were determined by reverse transcription polymerase chain reaction method. Measurement of neurotransmitters was performed by liquid chromatography tandem-mass spectrometry instrument. The accumulation of synuclein was demonstrated by immunohistochemical staining. In vitro thiazolyl blue tetrazolium bromide method was applied to determine the mitochondrial function of synaptosomal brain fractions using rotenone as a neurotoxic agent and mitoquinone and oleandrin as neuroprotective agents. Results: Mitoquinone improved the oxidant-antioxidant balance and neurotransmitter levels that were disrupted by rotenone. Mitoquinone also ameliorated the expressions of Parkinson's disease-related gene expressions that were disrupted by rotenone. According to thiazolyl blue tetrazolium bromide assay results, mitoquinone and oleandrin increased mitochondrial function which was decreased due to rotenone exposure. Conclusion: Based on the results of our study, positive effects of mitoquinone were observed in Parkinson's disease model induced by rotenone in zebrafish.

From epidemiology and neurometabolism to treatment: Vitamin D in pathogenesis of glioblastoma Multiforme (GBM) and a proposal for Vitamin D + all-trans retinoic acid + Temozolomide combination in treatment of GBM

Here we review tumoricidal efficacy of Vitamin D analogues in glioblastoma multiforme (GBM) and potential synergisms with retinoic acid and temozolomide based on epidemiological and cellular studies. Epidemiological data suggest that winter birth is associated with higher risk of GBM, and GBM debulking in the winter enhanced mortality, which may relate with lower exposure to sunlight essential to convert cholecalciferol to Vitamin D. Comparative studies on blood bank specimens revealed that higher prediagnosis levels of calcidiol are associated with lower risk of GBM in elderly men. Supplemental Vitamin D reduced mortality in GBM patients in comparison to nonusers. Expression of Vitamin D Receptor is associated with a good prognosis in GBM. Conversely, Vitamin D increases glial tumor synthesis of neutrophins NGF and NT-3, the low affinity neurotrophin receptor p75NTR, IL-6 and VEGF, which may enhance glioma growth. Antitumor synergisms between temozolomide and Vitamin D and Vitamin D with Vitamin A derivatives were observed. Hence, we hypothesize that Calcitriol + ATRA (All-Trans Retinoic Acid) + Temozolomide - CAT combination might be a safer approach to benefit from Vitamin D in the management of high-grade glial tumors. Adding acetazolomide to this protocol may reduce the risk of pseudotumor cerebri, as both Vitamin D and Vitamin A excess may cause intracranial hypertension; this approach may provide further benefit as acetazolomide also exhibits anticancer activity.

Vinorelbine's anti-tumor actions may depend on the mitotic apoptosis, autophagy and inflammation: hypotheses with implications for chemo-immunotherapy of advanced cancers and pediatric gliomas

Vinorelbine is a very potent chemotherapeutic agent which is used to treat a number of cancers including breast and non-small cell lung tumors. Vinorelbine mainly acts via blocking microtubules and induces a specific type of cell death called 'mitotic catastrophe/apoptosis' subsequent to mitotic slippage, which is the failure of cells to stay in a mitotic arrested state and replicating their DNA without cytokinesis. Glial tumor cells are especially sensitive to mitotic slippage. In recent years, vinorelbine demonstrated potency in pediatric optic and pontine gliomas. In this manuscript, we propose that vinorelbine's anti-tumor actions involve mitotic apoptosis, autophagy and inflammation. Intravenous infusion of vinorelbine induces a peculiar severe pain in the tumor site and patients with highly vascularized, oedematous and necrotic tumors are particularly vulnerable to this pain. Severe pain is a sign of robust inflammation and anti-inflammatory agents are used in treatment of this side effect. However, no one has questioned whether inflammation contributes to anti-tumor effects of vinorelbine, despite the existing data that vinorelbine induces Toll-Like Receptor-4 (TLR4), cytokines and cell death in endothelial cells especially under hypoxia. Robust inflammation may contribute to tumor necrosis such as seen during immunotherapy with lipopolysaccharides (LPS). Evidence also emerges that enhanced cyclooxygenase activity may increase cancer cell death in certain contexts. There are data indicating that non-steroidal anti-inflammatory drugs (NSAIDs) could block anti-tumor efficacy of taxanes, which also work mainly via anti-microtubule actions. Further, combining vinorelbine with immunostimulant cytokines provided encouraging results in far advanced melanoma and renal cell carcinoma, which are highly antigenic tumors. Vinorelbine also showed potential in treatment of inflammatory breast cancer. Finally, pontine gliomas - where partial activity of vinorelbine is shown by some studies - are also tumors which partially respond to immune stimulation. Animal experiments shall be conducted whether TLR4-activating molecules or immune-checkpoint inhibitors could augment anti-tumor actions of vinorelbine. Noteworthy, TLR4-activation seems as the most promising way of cancer immunotherapy, as a high percentage of molecules which demonstrated clinical benefits in cancer treatment are activators of TLR4, including BCG vaccine, monophosphoryl lipid A and picibanil (OKT-432). The provided data would be meaningful for the oncological practice.

From epidemiology and neurodevelopment to antineoplasticity. Medroxyprogesterone reduces human glial tumor growth in vitro and C6 glioma in rat brain in vivo

OBJECTIVE

Glial tumor growth may accelerate during gestation, but epidemiological studies consistently demonstrated that parousity reduces life long risk of glial tumors. Pregnancy may also accelerate growth of medulloblastoma and meningioma, but parousity does not confer protection against these tumors. We were the first to show that medroxyprogesterone acetate (MPA) reduces rat C6 glioma growth in vitro. Now we aimed to determine the effects of MPA on human brain cancers (particularly glioblastoma) in vitro and C6 glioma in vivo.

PATIENTS AND METHODS

We evaluated the effects of MPA on: i) monolayer growth of human U87 and U251 glioblastoma, ii) 3D-spheroid growth and invasion of C6 rat glioma and human U251 glioma, iii) interactions with PI3-Kinase inhibitors and coxsackie-adenovirus receptor (CAR) in modifying 3D-spheroid invasion of glioma.

RESULTS

MPA at low doses (3.25-13 μM) insignificantly stimulated and at high doses (above 52 μM) strongly suppressed the growth of human U87 and U251 cells in vitro. MPA also binds to glucocorticoid receptors similar to dexamethasone (Dex) and unexpectedly, PI3-Kinase inhibitors at low doses suppressed anti-invasive efficacies of MPA and Dex. MPA exerted higher invasion-inhibitory effects on CAR-expressing human glioma cells. Lastly, MPA suppressed growth of C6 glioma implanted into rat brain.

CONCLUSION

Progesterone analogues deserve to be studied in future experimental models of high grade glial brain tumors.

Management of Failed Cranioplasty

AIM

Failed cranioplasty attempts may lead to numerous complications in a broad spectrum including cosmetic problems, infection, neurological deterioration and even death. Selection of the most appropriate surgical technique for second and further surgical attempts for these patients still remains a debate. We aimed to share our experience and technical pitfalls on management of failed cranioplasty, particularly for patients with large cranial defects.

MATERIAL AND METHODS

A retrospective data analysis of cranioplasty cases in our series was performed including the time period between 2002 and 2012. Patients required recurrent cranioplasty were analyzed in detail.

RESULTS

Totally, 101 patients underwent cranioplasty for bony defect. Of 101 patients, eleven required a revision surgery due to infection or spontaneous resorption of the bone flap. All patients underwent revision cranioplasty with pre-surgical plaster cast mold technique modified from previous studies and/or tissue expansion technique. Polymethyl-metacrylate (PMMA) was used as substitute for reconstructions. Mean follow-up was 36 months. Two out of eleven cases (18.1%) developed major complications, which led to further revision. At the end, a satisfactory reconstruction was achieved for all patients.

CONCLUSION

Our modified molded plaster cast technique is a safe and cost-effective approach for the revision of failed cranioplasty. We believe that the tissue expanding techniques have also great contribution to achieve successful results.

MGMT gene variants, temozolomide myelotoxicity and glioma risk. A concise literature survey including an illustrative case

Temozolomide may cause thrombocytopenia or neutropenia in 3-4% of glioblastoma patients, respectively. However, pancytopenia is rarely reported. MGMT (O6-methylguanine-DNA-methyltransferase) enzyme repairs temozolomide-induced DNA mutations and associates both with antitumour efficacy and myelosuppression. Many studies on the effects of MGMT gene-methylation on temozolomide's effects exist, but much fewer publications concerning MGMT variants were documented. A full sequencing of the MGMT gene was performed in a female glioblastoma patient, who developed pancytopenia following temozolomide treatment. Results indicated the presence of all the rs2308321 (I143 V), rs2308327 (K178R) and rs12917 (L84F) MGMT-variants, which were previously associated with temozolomide myelotoxicity. rs12917 (L84F) variant was reported as associating with lesser risk of gallbladder tumours, yet with higher risk of non-Hodgkin lymphomas related with exposure to chlorinated solvents or hair dyes. DNA repair proteins may exert diverging effects on DNA injuries caused by different chemicals and therefore exerting complex effects on myelotoxicity, antitumour activity and carcinogenesis.

Multimodal Intraoperative Neurophysiological Monitoring in Spinal Cord Surgery

AIM

Intraoperative neurophysiological monitoring (IONM) monitors the functional integrity of critical neural structures by electrophysiological methods during surgery. Multimodality combines different neurophysiological methods to maximize diagnostic efficacy and provide a safety margin to improve the outcomes of spinal surgery. Our aim was to share our intraoperative monitoring experiences with patients who underwent surgery because of spinal cord pathologies between September 2013 and January 2015.

MATERIAL AND METHODS

We had twenty-six cases. Location of the lesions, surgery, neurological findings, and electrophysiological findings intraoperatively and postoperatively were documented.

RESULTS

The combination of motor evoked potential (MEP), somatosensorial evoked potential (SSEP), free-run and trigger electromyography (EMG) were performed according to lesion localization. MEPs plus SSEPs were run in 23 patients and MEPs with triggered EMG were performed in 4 patients. In only one patient, optimal recording could not be elicited because of technical problems. MEP and SSEP changes were recorded in 12 and 3 patients respectively. Postoperative neurological deficits were observed in 2 patients. Deficits were transient in one case and permanent in the other. While baseline MEP responses were either absent or low amplitude ( < 50 microvolt) in 7 patients, following resection they were either visible or increased in amplitude. Surgery was ended in one patient with C7-T2 intramedullary tumour after the right distal MEP response disappeared.

CONCLUSION

Multimodal IONM is an important method to monitor the neural structures under risk in spine surgery and to keep the surgery within safety limits, especially for intramedullary spinal cord lesion surgery.

Impact of 1p/19q codeletion on the diagnosis and prognosis of different grades of meningioma

BACKGROUND

Meningiomas are one of the most common tumours to affect the central nervous system. Genetic mutations are important in meningeal tumourigenesis, progression and prognosis. In this study, we aimed to examine the effect of 1p/19q deletion on the diagnosis and prognosis of meningioma subtypes using the fluorescence in situ hybridization (FISH) method.

METHODS

Twenty-four patients with meningioma were retrospectively studied. Tumour samples were obtained from 10 typical, 11 atypical and three anaplastic malignant meningiomas. The most representative tumour sections were screened for 1p/19q deletion using the FISH method.

RESULTS

Of the 24 patients, eight were women (33.3%) and 16 (66.7%) were men. The mean age was 56.6 years. The higher-grade meningioma was usually seen in males and had a higher rate of deletion on 1p (p = 0.001). There was a statistically significant difference between the grades and the rate of deletion on 19q (p = 0.042) and between the grades and the rates of polysomy, monosomy and amplification on 19q (p = 0.002; p = 0.001; p = 0.002, respectively). There was no statistical difference between 1p/19q codeletion and the grades of meningioma (p > 0.05). We detected higher level of Ki-67 in the condition of codeletion but did not find a statistical difference (p = 0.0553).

CONCLUSION

Deletion on 1p, as well as deletion, polysomy, monosomy and amplification on 19q, are detected more frequently in high grade meningiomas. This amplification is most likely due to the amplification of oncogenes.

Evaluation of the Association Between Matrix Metalloproteinase 11 and Intervertebral Disc Disease

AIM

The intervertebral disc starts to degenerate when a human being begins to stand and learn to walk. It is known that many extrinsic, intrinsic and genetic factors play a role in disc degeneration. In this study, we examined whether the matrix metalloproteinase 11 might be associated with intervertebral disc degeneration.

MATERIAL AND METHODS

Fifty-six patients with lumbar disc herniations who were operated at Göztepe Education and Research Hospital, Neurosurgery Clinic between September 2008 and December 2009 were prospectively reviewed. History and complaints were obtained from the case reports. Neuroradiological evaluation was performed with magnetic resonance imaging. Surgical findings of cases were reported in the operation notes. Microscopic posterior hemipartial laminectomy and discectomy were performed in all cases. Degenerated herniated disc material of all cases extracted during surgery was evaluated with immunohistochemical staining in Marmara University, Institute of Neurological Sciences, Pathology Laboratory.

RESULTS

Comparing the immunohistochemical staining of cases who were 50 years or younger and cases who were over 50 years old, statistical significance was determined.

CONCLUSION

Matrix metalloproteinase 11 has a role in degenerating intervertebral disc disease, but it is not the only factor. Matrix metalloproteinase 11 might be a genetic factor in young-middle aged patients.

Hemoglobins, Hemorphins, and 11p15.5 Chromosomal Region in Cancer Biology and İmmunity with Special Emphasis for Brain Tumors

In systemic cancers, increased hemolysis leads to extracellular hemoglobin (HB), and experimental studies have shown its provoking role on tumor growth and metastasis. However, investigations have shown that HB chains presented by tumor vascular pericytes or serum protein complexes of HB could also induce antitumor immunity, which may be harnessed to treat refractory cancers and brain tumors. Mounting recent evidence shows that expression of HBs is not restricted to erythrocytes and that HBs exist in the cells of lung and kidney, in macrophages, and in neurons and glia of the central nervous system (CNS). HBs mediate coping with hypoxia and free radical stress in normal and tumor cells, and they are increased in certain tumors including breast, lung, colon, and squamous cell cancers. Recent studies showed HBs in meningioma, in the cyst fluid of craniopharyngioma, in the cerebrospinal fluid (CSF) of pediatric patients with posterior fossa tumors, and in glioblastoma cell lines. Hemorphins, abundant brain peptides formed via HB-chain cleavage, exert opioid activity and antiproliferative and immunomodifier effects. Hence mutations in HBs may modify brain tumorigenesis via influencing hemorphins and perturbing regulations of immune surveillance and cell growth in the neuroectodermal tissues. The β-globin gene cluster resides in the chromosome region 11p15.5, harboring important immunity genes and IGF2, H19, PHLDA2/TSSC3, TRIM3, and SLC22A18 genes associated with cancers and gliomas. 11p15.5 is a prominent region subject to epigenetic regulation. Thus the β-globin loci may exert haplotypal interactions with these. Some clues support this theory. It is well established that iron load induces liver cancer in thalassemia major; however iron load-independent associations also exist. Enhanced rates of hematologic malignancies are associated with HB Lepore, association of hemoglobin E with cholangiocarcinoma, and enhanced gastric cancer rates in the thalassemia trait. In the African Herero population, a mutant form of δ-globin is very prevalent, and this population has higher rates of pediatric brain tumors. Globins are also expressed in healthy endothelia and in tumoral vessels, indicating potential involvement in angiogenesis. Studies on HBs and their cleavage peptides in cancers and brain tumors may lead to innovative treatment strategies.

Focal megalencephaly: intraoperative ultrasound imaging in epilepsy surgery

Hemimegalencephaly is a rare neuronal migration disorder that can be defined as abnormal neural and glial proliferation localized to all or part of a cerebral hemisphere. Most patients demonstrate intractable epilepsy, with early onset before 1 year of age. Surgical resection is one of the treatment options. In recent years, many advanced intraoperative techniques have been used for brain surgery for various pathologies. Intraoperative ultrasonography is a time-saving and noninvasive method for intraoperative imaging. In this report, we present the use of intraoperative ultrasonography in a patient with focal megalencephaly as an anatomical navigation with the functional navigation system, electrocorticography. In this report, we present the use of intraoperative ultrasonography in a patient with focal megalencephaly as an anatomical navigation with the functional navigation system, electrocorticography.

Relation of apparent diffusion coefficient with Ki-67 proliferation index in meningiomas

OBJECTIVE

The purpose of this study was to investigate the relationship between Ki-67 proliferation indexes and apparent diffusion coefficient (ADC) values of low-grade and atypical/anaplastic (high-grade) meningiomas.

METHODS

Pre-operative diffusion-weighted imaging and histopathological evaluation of 44 patients with meningiomas were performed retrospectively. Regions of interest (ROIs) were manually drawn on the ADC images. In total six ROI measurements were taken in three consecutive slices, and the average of the mean ADC value was used. The relationship between the ADC and Ki-67 values was investigated, and the ADC values of the low-grade and high-grade meningiomas were compared.

RESULTS

31 (70%) patients had low-grade the meningiomas. 10 (23%) patients had atypical and 3 (7%) had anaplastic meningiomas. ADC values of the low-grade and high-grade meningiomas were 0.81 ± 0.12 × 10(-3) and 0.66 ± 0.08 × 10(-3) mm(2) s(-1), respectively. Ki-67 proliferation indexes were 2.19% ± 1.14% for low-grade and 11.20% ± 9.80% for high-grade meningiomas. A statistically significant negative correlation between Ki-67 proliferation index and ADC values of the low-grade and high-grade meningiomas was detected (r(2) = 0.326, p < 0.001). High-grade meningiomas had lower ADC values than that of low-grade meningiomas. There was statistically significant difference between the ADC values of the low-grade and high-grade meningiomas (p < 0.001).

CONCLUSION

Our data provide an inverse correlation between the ADC and Ki-67 proliferation index values of meningiomas. ADC values can be used for histopathological characterization of the meningiomas and pre-surgical planning.

ADVANCES IN KNOWLEDGE

The purpose of this study was to investigate the relationship between Ki-67 proliferation indexes and ADC values of low-grade and atypical/anaplastic (high-grade) meningiomas. In addition, we compared the ADC and Ki-67 proliferative index values of the low-grade and atypical/anaplastic (high-grade) meningiomas. We concluded that there was an inverse correlation between the ADC and Ki-67 proliferation index values in meningiomas, and we have found statistically significant difference between the ADC values of the low-grade and high-grade meningiomas. ADC values can be used for histopathological characterization of the meningiomas and pre-surgical planning.

Spinal arteriovenous malformation: use of intraoperative color Doppler ultrasonography guidance for surgical resection. Case report

Spinal arteriovenous malformations (AVMs) may be associated with sensory and motor deficits, bowel or bladder dysfunction, radicular pain or deficit, and back pain. Hemorrhage can occur in the parenchyma leading to the acute onset of symptoms. Neurosurgical resection is one of the way of treatment. Several techniques including intraoperative angiography, dye-injection and the micro Doppler method have proven to be useful during the surgical resection of spinal vascular lesions. Herein, we report our experience with intraoperative ultrasonography (IOUS) and color Doppler ultrasonography guidance for visualizing a spinal cord AVM during surgery. IOUS is a time-saving and noninvasive method for intraoperative imaging of spinal AVM.

A new molecule in aneurysmal subarachnoid hemorrhage: dendroaspis natriuretic peptide

AIM

Dendroaspis natriuretic peptide (DNP) is the most recently identified member of the natriuretic peptide family. Although DNP has similar structure and function to other members, it is genetically different. The other members are known to cause vasorelaxation but the effects of DNP on vascular structure still remains unclear. In this study, we aimed to find out the role of DNP in the development of vasospasm following aneurysmal SAH (subarachnoid hemorrhage).

MATERIAL AND METHODS

DNP levels of 17 patients diagnosed with aneurysmal SAH and 25 volunteers as control were measured. All SAH patients were treated with aneurysm clip. Five ml of venous blood sample was obtained on postoperative 1, 3 and 7th days from each patient. Additionally, DNP levels were determined by obtaining cerebrospinal fluid (CSF) postoperative 1, 3 and 7th days.

RESULTS

Statistically significant difference was observed between cerebrospinal fluid DNP levels on day 1 and day 3 (P < 0.05).

CONCLUSION

This study suggests that DNP can be anticipated among molecules leading development of vasospasm. The findings of present study are believed to encourage further studies regarding receptors and receptor specific drugs.

The role of a single nucleotide polymorphism of the matrix metalloproteinase-1 gene promoter region in invasion and prognosis of meningiomas

AIM

The matrix metalloproteinase (MMP) enzyme family has been shown to be active in tumorigenesis and tumor progression. In this study, we analyzed the prevalence of a guanine insertion in the MMP-1 gene promoter region in meningiomas and its effect on invasion and prognosis.

MATERIAL AND METHODS

The study was performed with 33 meningioma patients. We also included 33 healthy patients in the study as a control group. The promoter area was amplified by polymerase chain reaction (PCR) following DNA isolation. The polymorphism was detected by restriction fragment length polymorphism (RFLP).

RESULTS

According to the WHO classification of meningiomas, 87.9% of the affected patients were grade 1, and 12.1% were grade 2. In total, 72.7% of the meningioma patients (n=24) had at least one copy of the insertion (2G/1G or 2G/2G genotypes) and 27.3% (n=9) did not (1G/1G). There was no significant difference between the meningioma and control groups according to genotype distribution.

CONCLUSION

In this study, the polymorphism in the matrix metalloproteinase-1 gene promoter region did not have an effect on the initiation, growth and progression of meningioma.

Desmoplastic infantile ganglioglioma: Report of an unusual case with a cranial defect

Desmoplastic infantile ganglioglioma (DIG) is a rare tumor that typically occurs in infants under the age of 24 months. These tumors commonly have a good prognosis after surgical resection despite their aggressive radiological appearances. Clinical signs are due to the large size of the tumor and include increased head circumference, bulging fontanel, sunset sign and seizures. We report an unusual DIG case who presented with parietal bulging associated with a bony defect. The patient was thought to have a leptomeningeal cystic formation, but on his cranial magnetic resonance imaging (MRI), we observed a centrally and homogeneously gadolinium-enhanced lesion fixed to the dura by its solid component. A surgical gross total resection was performed, and no residual tumor was observed on follow-up.

Diagnosis and management of pituitary abscess: a case series and review of the literature

AIM

Pituitary abscess is a disorder characterized with central nervous system (CNS) infection, mass effect, and endocrine dysfunction. These abscesses generally occur due to hematogenous spread in conditions such as paranasal sinusitis, sepsis, and where the blood brain barrier breaks down. This paper aims to discuss four cases of preoperatively diagnosed pituitary abscess in the light of the literature.

MATERIAL AND METHODS

Following detailed clinical and hormonal examinations and imaging tests, 210 cases of pituitary adenoma and other sellar pathologies were operated on at the Neurosurgery clinic of Göztepe Training and Research Hospital.

RESULTS

All the patients showed fever, systemic signs of toxemia and endocrine dysfunction at the time of diagnosis. In these cases, a preoperative diagnosis of the disease was made thanks to characteristic MRI findings. The four cases were operated by the transnasal transsphenoidal approach and histopathological and microbiological studies were performed for surgical specimens.

CONCLUSION

Pituitary abscesses are rare disorders responsible for a high mortality risk. Mortality and morbidity can be reduced by early surgical drainage and appropriate antibiotic treatments. Additionally, these cases should be closely followed-up in terms of pituitary insufficiency, surgical complications and infection.

Investigation of ACE genome insertion/deletion correlation with immunohistochemical profile in pituitary adenomas

AIM

The deletion polymorphism of the angiotensin-converting enzyme (ACE) genome causes neoplastic development in several organs by increasing the angiotensin 2 (A2) formation. In this study, we aimed to identify the ACE genome insertion/deletion polymorphism in pituitary adenomas and to compare it with the control group.

MATERIAL AND METHODS

Patients operated for pituitary adenomas were included in the study. Genomic DNA was extracted from tumoral tissues and peripheral blood samples of the patients by using the Miller method. Primary sequence was selected via targeting the polymorphic region of intron 16 of ACE genome 17q23. DNA samples were multiplied by PCR using HACE3s and HACE3as primers.

RESULTS

Twenty-one operated cases were studied. In the study group; 44 % of the patients were identified as D/D, 33% of them as I/D and 23% of them as I/I. In 60%, D allele was identified. According to immunohistochemical investigation, we found that 100% of the patients with Cushing adenoma were D/D alleles.

CONCLUSION

Presence of high rate of ACE genome deletion in patients with pituitary adenoma and grade 3-4 patients suggest that ACE genome polymorphism can be a risk factor for the development of pituitary adenomas.

Haemodynamic augmentation in the treatment of vasospasm in aneurysmal subarachnoid hemorrhage

AIM

Hypertension, hypervolemia and hemodilution therapy is a common approach to cerebral vasospasm after subarachnoid haemorrhage. This study is designed to see the difference of moderate or aggressive hypervolemia supported with induced hypertension in symptomatic vasospasm detected with transcranial Doppler ultrasonography (TCD) measurements.

MATERIAL AND METHODS

Fifty eight patients who had aneurysm clipping and were admitted to the neurointensive care unit were treated with normovolemia and induced hypertension (n=35) or hypervolemia supported with induced hypertension (n=23) targeting a mean arterial pressure of 110-130 mm Hg and central venous pressure of 8-12 mm Hg. Daily TCD, fluid intake, fluid balance and haemodynamic values were recorded for 14 days.

RESULTS

There were no differences detected in mean arterial pressure, central venous pressure, hematocrit values, fluid balance and middle cerebral artery flow velocities between the two groups through 14 days (p > 0.05). Hyponatremia, pulmonary edema and cerebral ischemia were observed as complications.

CONCLUSION

Hypervolemia adds no benefit compared to normovolemia in the treatment of vasospasm occurred as a result of subarachnoid hemorrhage. Induced hypertension establishes the haemodynamic augmentation to prevent and treat vasospasm.

Noninvasive estimation of cerebral perfusion pressure with transcranial Doppler ultrasonography in traumatic brain injury

AIM

In traumatic brain injury (TBI) patients, to overcome the secondary insults, cerebral perfusion pressure (CPP) oriented therapy is recommended. The study is assigned to estimate CPP values with middle cerebral artery (MCA) flow velocities measured noninvasively using transcranial Doppler ultrasonography (TCD).

MATERIAL AND METHODS

Forty-seven TBI patients were studied. Intracranial pressure (ICP), mean arterial pressure (MAP) and MCA flow velocities of the patients were monitored. Invasive CPP was calculated as the difference between MAP and ICP. The formula : 'MAP x FVd/FVm +14' was used to estimate CPP noninvasively. Correlation of the noninvasive and invasive values were analysed.

RESULTS

The mean values of noninvasive CPP and invasive CPP were 66.10 ± 10.55 mmHg and 65.40 ± 10.03 mmHg respectively. The correlation between noninvasive and invasive CPP measurements was strongly significant (p < 0.001) with a correlation coefficient of r = 0.920.

CONCLUSION

With ICP monitoring systems, CPP is calculated and the therapy is guided according to these values. As it is recognized that brain perfusion can be assessed with TCD waveforms, noninvasive CPP estimation with MCA flow velocities may help to observe the trends in CPP values.

Microsurgical management of non-neurofibromatosis spinal schwannoma

INTRODUCTION

The aim of this study is to assess the clinical properties and surgical results of patients diagnosed with spinal schwannomas without neurofibromatosis (NF) properties.

PATIENTS AND METHODS

The data obtained from 35 patients who underwent resection of spinal schwannomas were analyzed. All cases with neurofibromas and those with a known diagnosis of NF Type 1 or 2 were excluded. 35 patients underwent surgery for spinal schwannoma at our institution between January 1997 and 2010. The data were gathered retrospectively from medical records and included clinical presentation, tumor location and post-operative complications. All cases were surgically excised, and they were confirmed to be schwannomas by pathologists with histopathological sections in paraffin stained with hematoxylin-eosin.

RESULT

We treated 35 (20 males and 15 females) patients with spinal schwannomas. The mean age of the patients was 47.2 (between 13 and 76) years. Of the cases, six schwannomas were located in the cervical spine, four in the thoracic spine, two in cervico-thoracic area, 10 in the thoraco-lumbar area and 13 in the lumbar spine. Two patients had malignant schwannomas that were recurrent. Of the 35 cases, the schwannomas were intradural-extramedullary in 30 cases (86%), intradural-intramedullar in 2 cases (6%), and extradural in 3 cases (9%).

CONCLUSION

Spinal schwannomas may occur at any level of the spinal axis and are most frequently intradural-extramedullary. The most common clinical presentation is pain. Most of the spinal schwannomas in non-NF patients can be resected completely without or with minor post-operative deficits. This knowledge may help us to create a strategy for total resection of a spinal schwannomas.

Long-term results and complications of the syringopleural shunting for treatment of syringomyelia: a clinical study

BACKGROUND

The use of drains in the treatment of syringomyelia has a simple and immediate appeal. Syringopleural shunting in syringomyelia has produced good short-term results, but limited information is available on long-term effects. We analyzed the complications and long-term outcomes after syringopleural shunting for syringomyelia.

CLINICAL MATERIAL AND METHODS

Fourthy-four patients with large-sized syringomyelia underwent syringopleural shunting because of spinal cord compression between 1992 and 2010 in our clinic. Thirty-two patients had Chiari malformation type I (Group B), and 12 patients were associated with primary parenchymal cavitations (Group A). Their ages ranged from 14 to 71 years. Both craniovertebral decompression and syringopleural shunting were performed on 21 patients, whereas only syringopleural shunting was performed on another 21 patients.

RESULTS

The follow-up period ranged from 1 year to 17 years (mean: 9.1 years). There was no operative mortality. Early postoperative MRI revealed that syringes of 43 patients had collapsed. There were 9 (20.5%) minor complications in 9 patients, including temporary neurological deficits (6), respiratory distress (2) and headache (1). Seven (15.9%) serious complications [permanent neurological deficit (1), shunt migration (2), shunt misplacement (1), spinal instability (1), tethering (1), CSF over drainage (1)] were seen in five patients. Four of them were treated with a secondary operation. Three patients (3/9; 33.3%) who were treated by syringopleural shunt alone (Group B2) required craniovertebral decompression, although the shunt was functional. During long-term follow-up, three patients stabilized, five patients (11.3%) developed a worse neurological condition, and two of these patients died 10 and 7 years after surgery. Of all patients, 88.6% showed significant clinical improvement.

CONCLUSIONS

Although there were complications and failures, syringopleural shunting produced satisfactory results at long-term follow-up.

The surgical treatment of plagiocephaly

AIM

Anterior plagiocephaly usually occurs with premature synostosis of the ipsilateral half of the coronal suture. The forehead is flattened on the affected side, with a backward and upward displacement of the affected orbit. The bulging of the calvaria may occur in the contralateral parietal area.

MATERIAL AND METHODS

This article presents the surgical techniques used over 7 years to treat plagiocephalic children. Eleven patients with unilateral coronal synostosis treated during 2003-2010 were analyzed retrospectively. The study included reviews of pre and postoperative computed tomography scans, operative techniques, clinical outcomes and complications. Unilateral orbital advancement with "tongue in groove" was performed in 5, and bilateral orbital advancement in 6 cases. Pre and postoperative anthropometric measurements were used to document the amount of advancement of the elevated and recessed orbita, and the amount of withdrawal of the contralateral side.

RESULTS

The mean age of the patients at time of surgery was 11 months. The preoperative values of the orbital height and retrusion were 0.68 cm and 1.87 cm, respectively. They were recorded as -0.1cm and 0,63 cm, postoperatively. Mean follow-up was 36 months, neither neurological sequelae nor other significant complications were encountered.

CONCLUSION

The surgical corrections have resulted in significant improvements in skull shape and high patient/parent satisfaction.

Correlation of pulsatility index with intracranial pressure in traumatic brain injury

AIM

In traumatic brain injury (TBI) patients, it is desired to monitor the intracranial pressure (ICP) to assess the cerebral haemodynamics and guide the therapy. The study was designed to see if the pulsatility index (PI) measured by transcranial Doppler ultrasonography (TCD) predicts information about ICP values.

MATERIAL AND METHODS

In 52 TBI patients with Glasgow Coma Scale (GCS) score < 9, invasive intracranial monitoring and TCD ultrasonography for PI were performed through five days. ICP, cerebral perfusion pressure (CPP), PI values were recorded and calculated. The correlation and regression analysis between ICP, PI and CPP were investigated in the whole group and in patients with a Glasgow Outcome Score (GOS) of 3-5.

RESULTS

The decline in ICP and PI values was significant through five days. The correlation between ICP and PI was strongly significant (p < 0.0001) on days 1, 3 and 5. In patients with a GOS of 3-5, correlation of ICP and PI was also observed. The only significant correlation observed between CPP and PI was on day 5.

CONCLUSION

The strong correlation observed between ICP and PI through the management period of TBI patients can lead us to use TCD ultrasonography-derived PI as a guide if invasive monitoring is not available.

A new entity: Chiari Zero malformation and its surgical method

Recently, Iskandar et al described "Chiari Zero malformation" to characterize some kind of syringomyelia that exhibits classic Chiari-type symptoms with little to no herniation, but there is some dilemma about whether it is actually present. We presented a 38-year-old-man with a diagnosis of cervical syringomyelia. In his neurological examination, there was monoparesia at the left leg together with hypoesthesia below thoracal 7. He had initially been treated with syringopleural shunting successfully. Nine months after surgery, his syringomyelia had regrown and he clinically deteriorated. It was accepted as "a Chiari zero malformation". We performed craniovertebral decompression only. Although there was no tonsillar herniation, his syringomyelia was completely resolved and his neurological status was improved six months after the craniovertebral decompression, This case suggested that "Chiari zero malformation" description is remarkable and craniovertebral decompression is a suitable surgical approach for this entity.

The effect of polymorphisms in the promoter region of the MMP-1 gene on the occurrence and invasiveness of hypophyseal adenoma

BACKGROUND

The matrix metalloproteinase-1 enzyme (MMP-1, also called collagenase 1) plays a key role in turnover of collagen fibers in the intercellular matrix. Insertion of a guanine residue was found within the promoter region of the MMP-1 gene. We found that MMP-1 levels increased approximately twofold over normal when this insertion was present, enabling MMP-1 to facilitate tumor invasion and metastasis. MMP-1 is also believed to play a role in tumor development. The aim of our study is to investigate the effect of polymorphisms in the promoter region of the MMP-1 gene on the development of benign and invasive hypophyseal adenomas.

PATIENTS AND METHODS

Thirty patients with hypophyseal adenomas diagnosed by radiological examination underwent surgical removal, and the diagnosis was confirmed using immunohistochemical staining of the pathology specimens. We found that ten of these patients had invasive adenomas confirmed by radiological examination and immunohistochemical staining. DNA isolation was performed on all specimens, and 5-cc venous blood samples were obtained from all patients as well as 30 volunteers using the Qiagen QIAquick kit. Promoter regions of MMP-1 genes from the DNA samples were amplified using polymerase chain reaction (PCR) and primers designed for the site-directed mutation method. Following PCR, a guanine residue within the promoter region of the MMP-1 gene was identified using the restriction fragment length polymorphism method and the ALU I restriction enzyme. Three genotypes were detected in a genotyping assay: 2G/2G, 1G/2G, and 1G/1G.

RESULTS

Of the surgically treated patients, 36.6% had the 2G/2G genotype, 46.6% had the 1G/2G genotype, and 16.6% had the 1G/1G genotype. The 2G allele frequency was found to be 83.4%. In 90% of cases of invasive adenoma, a homozygous 2G/2G genotype was detected.

DISCUSSION

The risk for development of hypophyseal adenoma may be greater in patients with the 2G allele. In cases of existing hypophyseal adenoma, those with the homozygous 2G allele tend to be invasive.

Currarino triad: surgical management and follow-up results of four [correction of three] cases

The Currarino syndrome is a rare triad that is a combination of a presacral mass, a congenital sacral bony abnormality and an anorectal malformation. We present 4 children with complete Currarino triad who were diagnosed using MRI. Our aim was to report the neurosurgical management of Currarino syndrome in children. All of the patients had chronic constipation and pain in the lumbosacral region. In the plain radiograph, 3 patients had a sacral scimitar-shaped bony abnormality, and 1 patient had total sacral agenesis. There was a narrow anal canal or narrow ventrally displaced anus in all patients. Their anorectal malformations were characterized as anal stenoses (4 patients), associated with Hirschsprung's disease in 2 cases. In 3 patients, MRI showed tethered cord syndrome in addition to the presacral mass. There was hydrocephalus in 1 patient. Anal stenosis was treated by anal dilatation. In 2 patients, rectal biopsy and temporary colostomy (2 patients) had been performed previously due to Hirschsprung's disease. We performed a posterior procedure via lumbar and sacral partial laminectomy-laminoplasty and transdural ligation of the neck of the meningocele for anterior sacral meningoceles, or alternatively, tumor excision for other types of presacral lesions. Histopathologically, 3 were cases of anterior sacral meningoceles and 1 was a teratoma. One of them also had a spinal abscess. He required reoperation (twice) and appeared at the time to have improved with medical therapy. All patients improved and stabilized. There were no additional neurological deficits and no recurrence of the presacral mass over the follow-up period (6 years, on average). The family pedigree did not reveal any familial transmission pattern. In cases of Currarino triad, MRI can allow the characterization of the presacral masses. If it is an anterior sacral meningocele or a solid tumor without severe anorectal malformation, it can be managed with posterior lumbar and sacral procedures. Such approaches are performed easily by transdural ligation of the neck of the anterior sacral meningocele or through tumor excision.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in patients with familial multiple cerebral cavernous malformations

Cavernous malformations can occur in both sporadic and autosomal dominant forms. The aim of this study was to investigate the potential role of insertion/deletion (I/D) polymorphisms of the angiotensin-converting enzyme (ACE) gene in the development of cerebral cavernous malformations (CCM). Forty-one members of two families affected by familial CCM were included in this study. DNA was isolated from peripheral venous blood, and polymerase chain reaction analysis was used to detect I/D polymorphisms of the ACE gene, using HACE3s and HACE3as as primers. Only 10 participants had MRI-confirmed CCM. Of these 10 subjects, seven had the I/D, two had the D/D, and one had the I/I genotype. Of the remaining 31 subjects, 14 had the I/I, 13 had the I/D, and four had the D/D genotype. There was a greater proportion of subjects with the D allele among those with MRI-confirmed CCM than among those without (p<0.05). These results suggest that the D polymorphism of the ACE gene may be involved in the pathogenesis of familial CCM.

Immunohistochemical expression of SPARC is correlated with recurrence, survival and malignant potential in meningiomas

Meningioma is a common neoplasm that constitutes almost 30% of all primary central nervous system tumors and is associated with inconsistent clinical outcomes. The extracellular matrix proteins play a crucial role in meningioma cell biology and are important in tumor cell invasion and in progression to malignancy. SPARC (secreted protein, acidic and rich in cysteine) (osteonectin) is a matricellular glycoprotein that regulates cell function by interacting with different extracellular matrix proteins. The aim of this study was to evaluate the expression of SPARC with proliferation index, p53 reactivity in WHO grade 1 (benign), grade 2 (atypical) and grade 3 (anaplastic) meningiomas and correlate with clinical features of the patients, including location of the tumor, recurrence of the tumor and survival of patients. We studied 111 meningiomas, 69 being benign, 34 being atypical and eight being anaplastic meningiomas of various histological types. Using immunohistochemical analysis, we evaluated the expression of SPARC, Ki-67 (MIB-1) and p53 in meningiomas. Immunohistochemical scores of SPARC were determined as the sum of frequency (0-3) and intensity (0-3) of immunolabeling of the tumor cells. A high immunohistochemical score (4-6) for SPARC was more frequent in atypical and in anaplastic meningiomas than in benign meningiomas (p < 0.01). MIB-1 proliferation index showed significant association between tumor grades in meningiomas (p < 0.01). At the end of a follow-up period of 47.53 +/- 25.04 months, 30 tumors recurred. A high SPARC expression was significantly associated with tumor recurrence (p = 0.02). The immunoreactivity of p53 protein and MIB-1 score were significantly higher in recurrent meningiomas than in non-recurrent meningiomas. The cumulative survival of patients with high SPARC expression was significantly lower than patients with low SPARC expression. The high SPARC expression scores were predominantly identified in meningothelial, fibrous and chordoid meningiomas; low SPARC expression scores were mostly spotted in secretory and psammomatous meningiomas. Evaluating SPARC expression might help assessing recurrence risk and survival estimation in meningiomas.