Tumor volume and calcifications as indicators for preoperative differentiation of grade II/III diffuse gliomas.

PURPOSE: To retrospectively evaluate preoperative clinical factors for their ability to preoperatively differentiate malignancy grades in patients with incipient supratentorial grade II/III diffuse gliomas. METHODS: This retrospective study included 206 adult patients with incipient supratentorial grade II/III diffuse gliomas according to the 2016 World Health Organization classification of tumors of the central nervous system. The cohort included 136 men and 70 women, with a median age of 41 years. Preoperative factors included age, sex, presence of calcifications on computed tomography scans, and preoperative tumor volume measured using preoperative magnetic resonance imaging. RESULTS: In patients with oligodendrogliomas (IDH-mutant and 1p/19q-codeleted), calcifications were significantly more frequent (p = 0.0034) and tumor volume was significantly larger (p < 0.001) in patients with grade III tumors than in those with grade II tumors. Moreover, in patients with IDH-mutant astrocytomas, preoperative tumor volume was significantly larger (p = 0.0042) in patients with grade III tumors than in those with grade II tumors. In contrast, none of the evaluated preoperative clinical factors were significantly different between the patients with grade II and III IDH-wildtype astrocytomas. CONCLUSION: In adult patients with suspicison incipient supratentorial grade II/III diffuse gliomas, presence of calcifications and larger preoperative tumor volume might be used as preoperative indices to differentiate between malignancy grades II and III in oligodendrogliomas (IDH-mutant and 1p/19q-codeleted) and larger preoperative tumor volume might have similar utility in IDH-mutant astrocytomas.

T2-Fluid-attenuated inversion recovery (FLAIR) pseudoprogression in patients with anaplastic oligodendrogliomas treated with procarbazine, lomustine and vincristine (PCV) chemotherapy alone.

BACKGROUND: Pseudoprogression in gliomas has been extensively described after radiotherapy with or without chemotherapy, but not after chemotherapy alone. Here we describe the occurrence of pseudoprogression in patients with anaplastic oligodendrogliomas treated with postoperative procarbazine, lomustine and vincristine (PCV) chemotherapy alone. METHODS: We retrospectively reviewed the medical and radiological files of patients with 1p/19q codeleted, IDH-mutant anaplastic oligodendrogliomas treated with PCV chemotherapy alone who presented magnetic resonance imaging (MRI) modifications suggestive of tumour progression and in whom the final diagnosis was a pseudoprogression. RESULTS: We identified six patients. All patients underwent a surgical resection and were treated with PCV chemotherapy without radiotherapy. After a median of 11 months following the initiation of chemotherapy (range: 3-49 months), the patients developed asymptomatic white matter MRI modifications around the surgical cavity leading to the suspicion of a tumour progression. These modifications appeared as hyperintense on T2-fluid-attenuated inversion recovery (FLAIR) sequence, hypointense on T1 sequence, and lacked mass effect (0/6), contrast enhancement (0/6), restriction on diffusion-weighted imaging (0/4), relative cerebral blood volume (rCBV) increase on perfusion MRI (0/4), and hypermetabolism on 18 F-fluoro-L-dopa positron emission tomography (18 F-DOPA PET) scan (0/3). One patient underwent a surgical resection demonstrating no tumour recurrence; the five other patients were considered as having post-therapeutic modifications based on imaging characteristics. After a median follow-up of 4 years all patients were progression-free. CONCLUSIONS: Anaplastic oligodendroglioma patients treated with postoperative PCV chemotherapy alone occasionally develop T2/FLAIR hyperintensities around the surgical cavity that can wrongly suggest tumour progression. Multimodal imaging and close follow-up should be considered in this situation.

Apparent diffusion coefficient values effectively predict cell proliferation and determine oligodendroglioma grade.

This study aims to evaluate the value of conventional magnetic resonance imaging (MRI) features and apparent diffusion coefficient (ADC) values in differentiating oligodendroglioma of various grades and explore the correlation between ADC and Ki-67. The preoperative MRI data of 99 patients with World Health Organization (WHO) grades 2 (n = 42) and 3 (n = 57) oligodendroglioma confirmed by surgery and pathology were retrospectively analyzed. Conventional MRI features, ADCmean, ADCmin, and normalized ADC (nADC) were compared between the two groups. A receiver operating characteristic curve was used to evaluate each parameter's diagnostic efficacy in differentiating the two tumor types. Each tumor's Ki-67 proliferation index was also measured to explore its relationship with the ADC value. Compared with WHO2 grade tumors, WHO3 grade tumors had a larger maximum diameter and more significant cystic degeneration/necrosis, edema, and moderate/severe enhancement (all P < 0.05). The ADCmin, ADCmean, and nADC values of the WHO3 and WHO2 grade tumors were significantly different, and the ADCmin value most accurately distinguished the two tumor types, yielding an area under the curve value of 0.980. When 0.96 × 10-3 mm2/s was used as the differential diagnosis threshold, the sensitivity, specificity, and accuracy of the two groups were 100%, 93.00%, and 96.96%, respectively. The ADCmin (r = -0.596), ADCmean (r = - 0.590), nADC (r = - 0.577), and Ki-67 proliferation index values had significantly negative correlations (all P < 0.05). Conventional MRI features and ADC values are beneficial in the noninvasive prediction of the WHO grade and tumor proliferation rate of oligodendroglioma.

Secondary cerebellopontine angle oligodendroglioma after cranial irradiation: a case report and literature review.

PURPOSE/AIM: Cerebellopontine angle (CPA) oligodendrogliomas are very rare, and only three preoperative cases have been confirmed. Secondary CPA oligodendrogliomas after radiation therapy are exceptionally rare, and no other cases have been reported. CASE REPORT: We present a case of a 25-year-old male with CPA oligodendroglioma who experienced hearing loss in right ear with walking instability for more than 2 months. The patient underwent craniotomy in our hospital because of grade II astrocytoma of the right temporal lobe 10 years ago. Postoperative radiotherapy lasted for 30 days, and six rounds of chemotherapy were performed. Magnetic resonance imaging (MRI) of the head revealed a cystic lesion located in the right CPA. The patient underwent surgery without obvious complications, and the tumor was subtotally removed. Histopathological examination revealed a diagnosis of oligodendroglioma, World Health Organization (WHO) grade II. The patient was discharged on the tenth postoperative day with a good recovery. Two weeks after discharge, chemotherapy with temozolomide and radiotherapy were performed. The patient remained well at 8 months follow-up. CONCLUSIONS: To the best of our knowledge, no other cases of secondary CPA oligodendroglioma after cranial irradiation have been reported in the literature. Compared with general oligodendroglioma, the tumor has no typical calcification and is more aggressive. The cranial nerves in the CPA area are closely adhered, and the blood supply is abnormally rich. It is difficult to completely remove the tumor. Postoperative radiotherapy and chemotherapy should be carried out as soon as possible.

Low grade oligodendroglioma seeding around the 4th ventricle.

We report a 45 years old female patient with a left temporal grade II oligodendroglioma that recurred on the wall of the fourth ventricle at grade II oligodendroglioma.

Seizures in patients with IDH-mutated lower grade gliomas.

PURPOSE: Most patients with Lower Grade Gliomas (LGG) present with epileptic seizures. Since the advent of molecular diagnostics, more homogenous sub-entities have emerged, including the isocitrate dehydrogenase-mutated (IDH-mutated) astrocytomas and 1p19q-codeleted oligodendrogliomas. We aimed to describe the occurrence of seizures in patients with molecularly defined LGG pre- and postoperatively and to analyze factors affecting seizure status postoperatively. METHODS: A population-based cohort of 130 adult patients with IDH-mutated WHO grade 2 or 3 astrocytomas and oligodendrogliomas was assessed pertaining to seizure burden before and after surgery. RESULTS: Fifty-four (79.4%) patients with astrocytoma and 45 (72.6%) patients with oligodendroglioma had a history of seizures before surgery. At 12 months postoperatively, 51/67 (76.1%) patients with astrocytoma and 47/62 (75.8%) patients with oligodendrogliomas were seizure free. In a multivariable logistic regression analysis, lower extent of resection (EOR) (OR 0.98; 95% CI 0.97-1.00, p = 0.01) and insular tumor location (OR 5.02; 95% CI 1.01-24.87, p = 0.048) were associated with presence of seizures within 1 year postoperatively in the entire LGG cohort. In sub-entities, EOR was in a similar manner associated with seizures postoperatively in astrocytomas (OR 0.98; 95% CI 0.96-0.99, p < 0.01) but not in oligodendrogliomas (p = 0.34). CONCLUSION: Our results are well in line with data published for non-molecularly defined LGG with a large proportion of patients being seizure free at 1 year postoperative. Better seizure outcome was observed with increased EOR in astrocytomas, but this association was absent in oligodendrogliomas.

Distinct TERT promoter C228T and C250T mutations in a patient with an oligodendroglioma: A case report.

The majority of oligodendroglial tumors harbor mutations in the telomerase reverse transcriptase (TERT) gene (TERT) promoter and the isocitrate dehydrogenase 1/2 (IDH1/2) gene (IDH1/2), as well as 1p/19q codeletion. Generally, TERT promoter mutations, C250T and C228T, are mutually exclusive. We present a case of oligodendroglioma harboring both C250T and C228T mutations in TERT promoter. A 38-year-old man presented with grand mal seizures and underwent a resection surgery for a left frontal lobe tumor. He was pathologically diagnosed as having oligodendroglioma and was carefully observed. At 48 years of age, he underwent another resection surgery due to tumor regrowth, with the pathological diagnosis of anaplastic oligodendroglioma. Genetic analysis of the initial tumor specimen revealed IDH1 R132H mutation and both C250T and C228T mutations in TERT promoter. Using mutation-specific primers, two mutations were considered to be distributed in different alleles. In the tumor specimen obtained during the second surgery, IDH1 R132H mutation was detected to be similar to that of the initial specimen; however, only C228T mutation was detected in TERT promoter. The 1p/19q codeletion was detected in both the initial and recurrent tumor specimens. According to the sequencing data from the two tumor specimens, although TERT promoter mutation has been considered to be an early genetic event in the tumorigenesis of oligodendroglial tumors, it is likely that the C250T and C228T mutations in TERT promoter are subclonally distributed in the same tumor specimen of the present case.

Prognostic value of O-(2-[18F]-fluoroethyl)-L-tyrosine PET in relapsing oligodendroglioma.

PURPOSE: To assess the relationship between F-18-fluoro-ethyl-tyrosine positron emission tomography (FET-PET) parameters of relapsing oligodendroglioma and progression-free survival. MATERIAL AND METHODS: The relationship of clinical parameters, FET-PET parameters (SUVmax, TBRmax, BTV, time-activity curves) and progression-free survival was analyzed using univariate and multivariate analysis in 42 adult patients with relapsing oligodendroglioma. Kaplan-Meier analysis was used to assess survival. RESULTS: Patients who did not undergo surgical resection of their relapsing tumor had significantly lower PFS if the tumor exhibited an SUVmax above 3.40 than those with an SUVmax below 3.40 (13.1 ± 2.3 months vs. 47.3 ± 6.0 months, respectively, p < .001). Patients who underwent surgery had similar PFS as the aforementioned non-operated patients with low SUVmax (53.6 ± 6.7 months, p = .948). The same was true for TBRmax using a threshold of 3.03 (PFS 12.5 ± 2.4 months vs. 44.0 ± 6.3 months / 53.6 ± 6.7 months, respectively; p < .001 / p = .825). Also, subjects with BTV below 10 cm3 that did not undergo surgery had a similar PFS as subjects who underwent surgery (40.2 ± 6.0 months vs. 52.4 ± 8.9 months, respectively, p = .587). Subjects with BTV above 10 cm3 and without surgery had a significantly worse PFS (13.8 ± 3.3 months, p < .001). Multivariate analysis showed that the prognostication by clinical parameters is improved by adding TBRmax to the model (AUC 0.945 (95% CI: 0.881-1.000), true classification rate 88.1%). CONCLUSION: FET-PET may provide added value for the prognostication of relapsing oligodendroglioma in addition to clinical parameters.

Temporal lobe angiocentric glioma with oligodendroglioma-like areas: a rare association of an uncommon tumor. A case report with review of literature.

BACKGROUND: Angiocentric glioma (AG) is a relatively uncommon clinico-pathological entity that presents in childhood. Angiocentric glioma displays various histopathological features which resemble cortical ependymoma, astroblastoma, and pilomyxoid astrocytoma and schwannoma. The astrocytes in angiocentric glioma appear peculiarly elongated, bipolar in shape, and characteristically arranged around blood vessels. They resemble radial glia and tanycytes morphologically. Unlike ependymomas, AG is a diffusely infiltrating lesion and perivascular processes are often much thicker than those in classic ependymomas. CASE PRESENTATION: AG usually present clinically as seizures, often as medically intractable epilepsy. In the indexed case, apart from unusual presentation with features of raised intra-cranial tension, an unusual histological picture of a more cellular oligodendroglioma like component was also seen. CONCLUSION: The appropriate diagnosis is critical as AG is usually slowly growing and treatable by surgical excision alone.

Region-by-region analysis of PET, MRI, and histology in en bloc-resected oligodendrogliomas reveals intra-tumoral heterogeneity.

PURPOSE: Oligodendrogliomas are heterogeneous tumors in terms of imaging appearance, and a deeper understanding of the histopathological tumor characteristics in correlation to imaging parameters is needed. We used PET-to-MRI-to-histology co-registration with the aim of studying intra-tumoral 11C-methionine (MET) uptake in relation to tumor perfusion and the protein expression of histological cell markers in corresponding areas. METHODS: Consecutive histological sections of four tumors covering the entire en bloc-removed tumor were immunostained with antibodies against IDH1-mutated protein (tumor cells), Ki67 (proliferating cells), and CD34 (blood vessels). Software was developed for anatomical landmarks-based co-registration of subsequent histological images, which were overlaid on corresponding MET PET scans and MRI perfusion maps. Regions of interest (ROIs) on PET were selected throughout the entire tumor volume, covering hot spot areas, areas adjacent to hot spots, and tumor borders with infiltrating zone. Tumor-to-normal tissue (T/N) ratios of MET uptake and mean relative cerebral blood volume (rCBV) were measured in the ROIs and protein expression of histological cell markers was quantified in corresponding regions. Statistical correlations were calculated between MET uptake, rCBV, and quantified protein expression. RESULTS: A total of 84 ROIs were selected in four oligodendrogliomas. A significant correlation (p < 0.05) between MET uptake and tumor cell density was demonstrated in all tumors separately. In two tumors, MET correlated with the density of proliferating cells and vessel cell density. There were no significant correlations between MET uptake and rCBV, and between rCBV and histological cell markers. CONCLUSIONS: The MET uptake in hot spots, outside hotspots, and in infiltrating tumor edges unanimously reflects tumor cell density. The correlation between MET uptake and vessel density and density of proliferating cells is less stringent in infiltrating tumor edges and is probably more susceptible to artifacts caused by larger blood vessels surrounding the tumor. Although based on a limited number of samples, this study provides histological proof for MET as an indicator of tumor cell density and for the lack of statistically significant correlations between rCBV and histological cell markers in oligodendrogliomas.

Extent of resection and survival for oligodendroglioma: a U.S. population-based study.

BACKGROUND: National guidelines recommend maximal safe resection of low-grade and high-grade oligodendrogliomas. However, there is no level 1 evidence to support these guidelines, and recent retrospective studies on the topic have yielded mixed results. OBJECTIVE: To assess the association between extent of resection (EOR) and survival for oligodendrogliomas in the general U.S. METHODS: Cases diagnosed between 2004 and 2013 were selected from the Surveillance, Epidemiology, and End-Results (SEER) Program and retrospectively analyzed for treatment, prognostic factors, and survival times. Cases that did not undergo tumor de-bulking surgery (e.g. no surgery or biopsy alone) were compared to subtotal resection (resection) and gross-total resection (GTR). The primary end-points were overall survival (OS) and cause-specific survival (CSS). An external validation cohort with 1p/19q-codeleted tumors was creating using the TCGA and GSE16011 datasets. RESULTS: 3135 Cases were included in the final analysis. The 75% survival time (75ST) and 5-year survival rates were 47 months and 70.8%, respectively. Subtotal resection (STR, 75ST = 50 months) and GTR (75ST = 61 months) were associated with improved survival times compared to cases that did not undergo surgical debulking (75ST = 20 months, P < 0.001 for both), with reduced hazard ratios (HRs) after controlling for other factors (HR 0.81 [0.68-0.97] and HR 0.65 [0.54-0.79], respectively). GTR was associated with improved OS in both low-grade and anaplastic oligodendroglioma subgroups (HR 0.74 [0.58-0.95], HR 0.60 [0.44-0.82], respectively) while STR fell short of significance in the subgroup analysis. All findings were corroborated by multivariable analysis of CSS and externally validated in a cohort of patients with 1p19q-codeleted tumors. CONCLUSION: Greater EOR is associated with improved survival in oligodendrogliomas. Our findings in this U.S. population-based cohort support national guidelines.

Resting-state network mapping in neurosurgical practice: a review.

Resting-state functional MRI (rs-fMRI) is a well-established method for studying intrinsic connectivity and mapping the topography of functional networks in the human brain. In the clinical setting, rs-fMRI has been used to define functional topography, typically language and motor systems, in the context of preoperative planning for neurosurgery. Intraoperative mapping of critical speech and motor areas with electrocortical stimulation (ECS) remains standard practice, but preoperative noninvasive mapping has the potential to reduce operative time and provide functional localization when awake mapping is not feasible. Task-based fMRI has historically been used for this purpose, but it can be limited by the young age of the patient, cognitive impairment, poor cooperation, and need for sedation. Resting-state fMRI allows reliable analysis of all functional networks with a single study and is inherently independent of factors affecting task performance. In this review, the authors provide a summary of the theory and methods for resting-state network mapping. They provide case examples illustrating clinical implementation and discuss limitations of rs-fMRI and review available data regarding performance in comparison to ECS. Finally, they discuss novel opportunities for future clinical applications and prospects for rs-fMRI beyond mapping of regions to avoid during surgery but, instead, as a tool to guide novel network-based therapies.

IDH-1 polymorphisms in pilocytic astrocytomas.

As of 2016, isocitrate dehydrogenase (IDH)-1 and IDH-2 mutations are part of the definition of an oligodendroglioma and may be seen in a significant subset of grade II-IV fibrillary astrocytomas. Reports of IDH-1 and IDH-2 alterations in pilocytic astrocytomas have been rare. This study reports two cases of pilocytic astrocytomas which harbored IDH-1 polymorphisms (G105G) (c.315C > T) discovered on polymerase chain reaction (PCR) testing and sequencing. The first was encountered in a 21-year-old male with a right orbital frontal pole mass. The second occurred in a 19-year-old female with a right frontal tumor. Neither tumor stained with antibody to IDH-1 (R132H). No BRAF V600E immunostaining, minimal p53 staining (<5%) and no loss of ATRX staining was noted in both cases. The significance of the IDH-1 findings at this juncture is uncertain. Misdiagnosis of the tumor as a fibrillary astrocytoma or oligodendroglioma due to the presence of an IDH alteration should be avoided.

Multicentric high grade oligodendroglioma: a rare entity.

A 74 year old male presented with 1 month history of weakness in right upper limb and motor aphasia for 15 days. Magnetic resonance imaging (MRI) of the brain showed three discrete ring enhancing lesions. An image guided awake craniotomy and biopsy of a lesion was performed. The histopathological examination revealed it to be a grade III Oligodendroglioma. This was a rare case of multicentric high grade oligodendroglioma has never been reported in literature. We report such a case with relevant review of literature.

Reconstruction of cranioplasty using the thoracodorsal artery perforator (TDAP) flap: A case series.

BACKGROUND: Complex defects resulting in ablation of the scalp, the calvaria, the dura, and the underlying brain are still challenging. These defects require cranioplasty to restore the bone cosmetic and functional roles and free-flap soft tissue reconstruction to prevent cranioplasty exposure and further infection. Different materials have been used in cranioplasty, while different free flaps have been proposed in those cases. In this article, we present a case series of cranioplasty reconstruction with thoracodorsal artery perforator flap (TDAP). PATIENTS AND METHODS: From April 2016 to January 2018, 5 patients underwent cranioplasty reconstruction using alloplastics and TDAP flap. Two patients underwent primary cranioplasty and 3 patients underwent secondary cranioplasty. The superficial temporal vessels were always dissected as recipient vessels. RESULTS: The flap sizes range from 40 to 80 cm2 (mean 57 cm2 ) and the maximum pedicle length was 12 cm (mean 10 cm). All the donor sites were closed primary with minimal morbidity. No postoperative complications were experienced. All the flaps provided stable coverage with an acceptable color match. The mean follow-up time was 4 months. CONCLUSIONS: Our data suggest that the TDAP may be employed in postcranioplasty reconstruction. The TDAP has more advantages compared to other flaps used in alloplastic reconstruction: a broad large surface, a long pedicle, and a thinner thickness.

The prognostic value of maximal surgical resection is attenuated in oligodendroglioma subgroups of adult diffuse glioma: a multicenter retrospective study.

PURPOSE: Maximal surgical resection is associated with survival benefit in the majority of studies in adult diffuse glioma. This study aims to characterize the prognostic value of surgical resection in molecular subgroups of diffuse glioma. METHODS: 1178 patients with diffuse glioma from our centers and 422 from TCGA dataset were collected. The Kaplan-Meier analysis and multivariable Cox regression models were conducted to identify the prognostic value of surgical resection through different histological and molecular stratifications. RESULTS: Firstly, we confirmed progression-free survival (PFS) benefit associated with gross total resection (GTR) over sub-total resection (STR) in lower-grade glioma (HR 1.49; 95% CI 1.17-1.90; P = 0.001). Intriguingly however, we were unable to detect a significant PFS or overall survival (OS) benefit in oligodendroglioma (N = 397; HR 1.36; 95% CI 0.86-2.14; P = 0.19 and HR 1.05; 95% CI 0.55-1.99; P = 0.89, respectively). Secondly, when analyzed in molecular subgroups, we were similarly unable to detect a significant PFS or OS benefit in IDH MT/codel subgroup (N = 269; HR 1.47; 95% CI 0.92-2.34; P = 0.11 and HR 1.54; 95% CI 0.78-3.05; P = 0.21, respectively), oligodendroglioma with IDH MT/codel subgroup (N = 233; HR 1.33; 95% CI 0.79-2.21; P = 0.28 and HR 1.16; 95% CI 0.53-2.54; P = 0.70, respectively) or other relevant subgroups. TCGA validation also showed a significant survival benefit in astrocytoma rather than oligodendroglioma. Exploratory RNAseq analysis displayed that fewer cell proliferation-related gene expression features were specific to oligodendroglioma. CONCLUSION: These results suggest that the benefit of maximal surgery may be attenuated in patients within oligodendroglioma relevant subgroups because of the chemosensitive and indolent nature. The aggressive surgery accompanying with risk of neurologic morbidity may be unnecessary for these patients given the lack of survival benefit with gross total resection.

[Li-Fraumeni syndrome in a patient with multiple anaplastic oligodendrogliomas of the brain (a case report and literature review)]. / Sindrom Li-Fraumeni u patsienta so mnozhestvennymi anaplasticheskimi oligodendrogliomami golovnogo mozga (klinicheskoe nabliudenie i obzor literatury).

Li-Fraumeni syndrome (LFS) is a clinically and genetically heterogeneous hereditary syndrome with predominantly oncological manifestations, which is associated with mutations in the TP53, MDM2, and CHEK2 genes. The most common variant is a TP53 mutation. OBJECTIVE: To analyze the literature and present a clinical case of a patient with Li-Fraumeni syndrome and multiple anaplastic oligodendrogliomas of the brain. CLINICAL CASE: A 42-year-old male patient presented with complaints of headaches, word finding difficulty, memory loss, right hemianopsia, and generalized convulsive attacks. For 10 years, he underwent multiple interventions and chemotherapy courses for colon adenocarcinoma and recurrent B-cell lymphoma. MRI revealed multiple space-occupying lesions of the cerebraln hemispheres, which were located in the left temporo-occipital and right frontal regions. RESULTS: The patient underwent resection of multiple space-occupying lesions of the left temporo-occipital and right frontal regions. The postoperative period proceeded without complications. The histological diagnosis was WHO grade III anaplastic oligodendroglioma. The patient and one of his sons were detected with a R248W missense mutation in the TP53 gene. The patient underwent six courses of temozolomide chemotherapy. At a follow-up examination 20 months after surgery and chemotherapy, the patient's condition was satisfactory; he returned to work. Control MRI of the brain revealed no signs of continued tumor growth. CONCLUSION: An analysis of the literature and the clinical case indicate the success of multiple surgical interventions and chemotherapy courses performed for a long time in the patient with Li-Fraumeni syndrome manifested by colon adenocarcinoma, recurrent B-cell lymphoma, and multiple anaplastic oligodendroglioma of the brain. The patient had a good quality of life and returned to professional activity.

Oligodendroglial cell proliferation arising in an ovarian mature cystic teratoma. Clinicopathological, inmunohistochemical, and ultrastructural study of a case that may represent an oligodendroglioma.

Ovarian mature cystic teratoma (OMCT) is an ovarian benign neoplasm with excellent prognosis presenting components of the three germinal layers. However, transformation into a malignant neoplasm is a rare event (so-called somatic transformation). In most of the cases, the malignant component expresses as epidermoid carcinoma, but occasionally central nervous system tumors occur. Some of the previously reported tumors are astrocytoma, glioblastoma, and ependymoma. Somatic transformation of OMCT into an oligodendroglioma is exceptional. We report a 19-year-old female with a left OMCT with an area of oligonedroglial cells proliferation characterized by immunohistochemical studies with positivity for GFAP and S100, with a low Ki67 index (5%). Additionally, electron microscopy revealed oligodendrocytes with parallel bundles of cytoplasmic intermediate filaments, confirming the oligodendroglial nature of the proliferation. The patient was treated only with left oophorectomy, and three and half years after surgery, there is no evidence of disease.

Pica in a Child with Anterior Cingulate Gyrus Oligodendroglioma: Case Report.

The anterior cingulate gyrus (ACG) is a continued focus of research as its exact role in brain function and vast connections with other anatomical locations is not fully understood. A review of the literature illustrates the role the ACG likely plays in cognitive and emotional processing, as well as a modulating role in motor function and goal-oriented behaviors. While lesions of the cingulate gyrus are rare, each new case broadens our understanding of its role in cognitive neuroscience and higher order processing. The authors present the case of an 8-year-old boy with a 1-month history of staring spells, agitated personality, and hyperphagia notable for the consumption of paper, who was found to have a 3-cm tumor in the left ACG. Following surgical resection of the tumor, his aggressive behavior and pica were ameliorated and the patient made an uneventful recovery, with no evidence of recurrence over the last 6 years since surgical resection. Here we discuss a unique behavioral presentation of pica, along with a review of the current literature, to illustrate functions of the ACG relevant to the location of the lesion.

Serious and reversible levetiracetam-induced psychiatric symptoms after resection of frontal low-grade glioma: two case histories.

Levetiracetam may induce serious behavioral disturbances, especially after surgical resection of frontal lobe low-grade glioma. Two patients, treated with levetiracetam, developed serious psychiatric complications postoperatively which completely resolved after switching to valproate. We aim to create awareness for this serious but reversible adverse effect of levetiracetam in this specific patient category.