Diagnostic and Therapeutic Challenges of Rare Concurrent Intracranial Meningioma and Oligodendroglioma.

Introduction: Concurrent primary brain tumors are rare clinical entities, with a prevalence ranging from 0.1 to 0.5% of all diagnosed brain tumors. The co-occurrence of meningioma and oligodendroglioma is particularly uncommon, posing unique diagnostic and therapeutic challenges. We describe the case of a patient diagnosed with concurrent meningioma and oligodendroglioma and review the existing literature on this rare phenomenon. Case Presentation: A 55-year-old female patient with a history of seizures presented to the emergency department with worsening headaches, nausea, and vomiting. She had a known right frontoparietal intracranial mass but had previously declined surgery. Magnetic resonance imaging revealed extensive fluid-attenuated inversion recovery /T2 hyperintensity around the lesion, which had slowly increased over 5 years; the growth of the lesion was producing a mass effect with a significant midline shift. The patient underwent urgent hemicraniectomy with subsequent resection. Clinical evaluation, imaging studies, and histopathological examination were conducted to confirm the diagnosis. Genetic and molecular analyses were also performed to explore potential underlying mechanisms. Histopathological findings confirmed a diagnosis of an isocitrate dehydrogenase-mutated World Health Organization Grade II oligodendroglioma with 1p/19q codeletion, along with a Grade I meningioma. Conclusion: The coexistence of meningioma and oligodendroglioma represents a rare clinical event. Surgical management remains the cornerstone of treatment. Further investigation into the genetic and environmental factors that contribute to the co-occurrence of such tumors could pave the way for more targeted therapeutic strategies.

Morphological and ultrastructural investigation of the posterior atlanto-occipital membrane: Comparing children with Chiari malformation type I and controls.

INTRODUCTION: The fibrous posterior atlanto-occipital membrane (PAOM) at the craniocervical junction is typically removed during decompression surgery for Chiari malformation type I (CM-I); however, its importance and ultrastructural architecture have not been investigated in children. We hypothesized that there are structural differences in the PAOM of patients with CM-I and those without. METHODS: In this prospective study, blinded pathological analysis was performed on PAOM specimens from children who had surgery for CM-I and children who had surgery for posterior fossa tumors (controls). Clinical and radiographic data were collected. Statistical analysis included comparisons between the CM-I and control cohorts and correlations with imaging measures. RESULTS: A total of 35 children (mean age at surgery 10.7 years; 94.3% white) with viable specimens for evaluation were enrolled: 24 with CM-I and 11 controls. There were no statistical demographic differences between the two cohorts. Four children had a family history of CM-I and five had a syndromic condition. The cohorts had similar measurements of tonsillar descent, syringomyelia, basion to C2, and condylar-to-C2 vertical axis (all p>0.05). The clival-axial angle was lower in patients with CM-I (138.1 vs. 149.3 degrees, p = 0.016). Morphologically, the PAOM demonstrated statistically higher proportions of disorganized architecture in patients with CM-I (75.0% vs. 36.4%, p = 0.012). There were no differences in PAOM fat, elastin, or collagen percentages overall and no differences in imaging or ultrastructural findings between male and female patients. Posterior fossa volume was lower in children with CM-I (163,234 mm3 vs. 218,305 mm3, p<0.001), a difference that persisted after normalizing for patient height (129.9 vs. 160.9, p = 0.028). CONCLUSIONS: In patients with CM-I, the PAOM demonstrates disorganized architecture compared with that of control patients. This likely represents an anatomic adaptation in the presence of CM-I rather than a pathologic contribution.

Papillary tumor of the pineal region: analysis of DNA methylation profiles and clinical outcomes in 76 cases.

Papillary tumor of the pineal region (PTPR) is an uncommon tumor of the pineal region with distinctive histopathologic and molecular characteristics. Experience is limited with respect to its molecular heterogeneity and clinical characteristics. Here, we describe 39 new cases and combine these with 37 previously published cases for a cohort of 76 PTPR's, all confirmed by methylation profiling. As previously reported, two main methylation groups were identified (PTPR-A and PTPR-B). In our analysis we extended the subtyping into three subtypes: PTPR-A, PTPR-B1 and PTPR-B2 supported by DNA methylation profile and genomic copy number variations. Frequent loss of chromosome 3 or 14 was found in PTPR-B1 tumors but not in PTPR-B2. Examination of clinical outcome showed that nearly half (14/30, 47%) of examined patients experienced tumor progression with significant difference among the subtypes (p value = 0.046). Our analysis extends the understanding of this uncommon but distinct neuroepithelial tumor by describing its molecular heterogeneity and clinical outcomes, including its tendency towards tumor recurrence.