Browsing by Subject "Ganglioglioma"

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    Diffuse leptomeningeal glioneuronal tumor with distinct neuronal and glial components but identical diagnostic molecular and genetic features
    (Wiley, 2024) Witten, Andrew J.; Dougherty, Carson; Hao, Chunhai; Neurological Surgery, School of Medicine
    The 2021 World Health Organization (WHO) classification of the central nervous system (CNS) tumors has classified diffuse leptomeningeal glioneuronal tumor (DLGNT) as a mixed neuronal and glial tumor. Here, we report a DLGNT with two distinct morphological tumor components but identical molecular features. A four-year-old female child presented with progressive right upper extremity weakness. Magnetic resonance imaging (MRI) revealed the leptomeningeal enhancement over the brain stem and cervicothoracic spine. The histological examination of surgical specimens revealed two distinct tumor components: approximately half of the tumor is composed of oligodendroglioma-like tumor intermingled with nodules of ganglioglioma-like tumor. Immunohistochemistry confirmed the oligodendroglioma and ganglioglioma features. The molecular genetic studies demonstrated the features of DLGNT, including fusion of KIAA1549::BRAF, deletion of chromosome 1p, and absence of isocitrate dehydrogenase 1/2 (IDH1/2) mutation in both tumor components. Interestingly, the genetic studies also revealed the distinct chromosomal abnormalities of the loss of chromosome 4 only in oligodendroglioma-like tumor and copy neutral loss of heterozygosity of 7Q34Q36.3 in the ganglioglioma-like tumor component. This case highlights the critical role of molecular testing in the diagnosis of rare cases of DLGNT with diverse morphological components as well as in the identification of unique molecular alternations responsible for morphological phenotypes of the distinct tumors in DLGNT.
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    Diffusion Imaging for Tumor Grading of Supratentorial Brain Tumors in the First Year of Life
    (American Society of Neuroradiology, 2014-04) Kralik, S.F.; Taha, A.; Kamer, A.P.; Cardinal, J.S.; Seltman, T.A.; Ho, C.Y.; Radiology and Imaging Sciences, School of Medicine
    Background and purpose: Supratentorial tumors in the first year of life are typically large and heterogeneous at presentation, making differentiation of these CNS neoplasms on pre-operative imaging difficult. We hypothesize that the ADC value can reliably differentiate high- versus low-grade supratentorial tumors in this patient population. Materials and methods: A blinded review of ADC maps was performed on 19 patients with histologically proved supratentorial brain tumors diagnosed within the first year of life. Minimum ADC values obtained by region of interest from 2 neuroradiologists were averaged and compared with World Health Organization tumor grade. ADC values for the entire tumor were also obtained by use of a semi-automated histogram method and compared with World Health Organization tumor grade. Data were analyzed by use of Spearman ρ and Student t test, with a value of P < .05 considered statistically significant. Results: For the manual ADC values, a significant negative correlation was found between the mean minimum ADC and tumor grade (P = .0016). A significant difference was found between the mean minimum ADC of the low-grade (1.14 × 10(-3) mm(2)/s ± 0.30) and high-grade tumors (0.64 × 10(-3) mm(2)/s ± 0.28) (P = .0018). Likewise, the semi-automated method demonstrated a significant negative correlation between the lowest 5th (P = .0002) and 10th (P = .0009) percentile individual tumor ADC values and tumor grade, a significant difference between the mean 5th and 10th percentile ADC values of the low-grade and high-grade groups (P = .0028), and a significant positive correlation with values obtained by manual region-of-interest placement (P < .000001). Conclusions: ADC maps can differentiate high- versus low-grade neoplasms for supratentorial tumors presenting in the first year of life, given the significant negative correlation between ADC values and tumor grade.