Astroblastoma With a Novel YAP1::BEND2 Fusion: A Case Report.

In the most recent fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System, astroblastoma has been defined by molecular rearrangements involving the MN1 gene, with common partners being BEND2 or CXXC5. Accordingly, this tumor entity is now known as "astroblastoma, MN1-altered." However, gliomas with EWSR1::BEND2 fusions, devoid of MN1 fusion alterations, have recently been shown to exhibit astroblastoma-like histomorphologic features and reside in a distinct epigenetic subgroup based on DNA methylation studies similar to high-grade neuroepithelial tumor with MN1 alteration, which includes astroblastoma, MN1 altered tumors. This new epigenetically distinct subtype of astroblastoma containing EWSR1::BEND2 fusions lacks the required MN1 alteration and, thus, does not satisfy the current molecular classification of these lesions. Here, we describe a case of glioma with histologic features and DNA methylation profiling consistent with astroblastoma with a novel YAP1::BEND2 fusion. This case and others further expand the molecular findings observable in astroblastoma-like tumors outside the constraints of MN1 alteration. Such cases of astroblastoma with EWSR1::BEND2 and YAP1::BEND2 fusions challenge the current molecular classification of astroblastoma based solely on an MN1 alteration.

Central Nervous System Lymphoproliferative Disorder Secondary to Methotrexate: A Systematic Literature Review and Case Illustration.

BACKGROUND: Methotrexate is an immunosuppressant commonly used to treat inflammatory conditions, such as rheumatoid arthritis. However, albeit exceedingly rare, it can have serious adverse effects within the central nervous system (CNS), such as methotrexate-associated lymphoproliferative disorder (MTX-LPD). Literature describing the natural history, treatment options, and clinical outcomes of patients with CNS MTX-LPD remains sparse. METHODS: We present a systematic literature review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and a case illustration of CNS MTX-LPD. RESULTS: A systematic review of the literature revealed 12 published cases of CNS MTX-LPD, plus the case presented herein, for a total of 13 included cases. The most common indication for MTX was rheumatoid arthritis. The most common treatment for the LPD was MTX cessation (12, 92.3%), adjunct chemotherapy (2, 15.4%), total tumor resection (3, 23.1%), or steroid therapy (1, 7.7%). Treatment usually led to improvement of neurological symptoms (9, 69.2%) along with regression of the lesions (3, 23.1%) with no recurrence (6, 46.2%). Death was reported in four cases (30.8%) with a mean time from onset of 11 months. CONCLUSIONS: CNS MTX-LPD should be considered in the differential diagnosis for patients who are taking MTX presenting with neurologic symptoms, as immediate withdrawal of MTX has demonstrated good prognosis.

Pediatric diffuse hemispheric glioma H3 G34-mutant with gains of the BRAF locus: An illustrative case.

Diffuse hemispheric glioma, H3 G34-mutant, is a recently recognized distinct high-grade glioma with a dismal prognosis. In addition to the H3 G34 missense mutation, numerous genetic events have been identified in these malignant tumors, including ATRX, TP53, and, rarely, BRAF genes. There are only a few reports to date that have identified BRAF mutations in diffuse hemispheric glioma, H3 G34-mutant. Moreover, to our knowledge, gains of the BRAF locus have yet to be described. Here, we present a case of an 11-year-old male with a diffuse hemispheric glioma, H3 G34-mutant, found to have novel gains of the BRAF locus. Furthermore, we emphasize the current genetic landscape of diffuse hemispheric glioma, H3 G34-mutant, and implications of an aberrant BRAF signaling pathway.

Kikuchi-Fujimoto Disease: A Differential for When It is Not Systemic Lupus Erythematosus.

Kikuchi-Fujimoto disease (KFD) is a rare and benign disease process that is characterized by fever and lymphadenopathy that was first described in young Japanese women in the early 1970s. Knowledge of KFD is important as it can often mimic other causes of lymphadenopathy including systemic lupus erythematosus (SLE) or malignancies, and this can lead to invasive diagnostic testing and even treatments that can be avoided. The etiology and exact mechanism by which KFD develops is not fully understood at this time, but is thought to be an immune response of T cells and histiocytes to viral or bacterial infections. We present a 35-year-old African-American woman who was referred to the rheumatology clinic by our colleagues in the breast clinic with new onset right axillary lymphadenopathy and abnormal serologic testing with the suspicion of SLE after a malignancy had been ruled out.

Supratentorial cortical ependymoma: A systematic literature review and case illustration.

Cortical ependymomas are currently not considered a subgroup of supratentorial ependymomas; however, there is a growing body of literature investigating the natural history of these lesions compared to supratentorial ependymomas. We performed a systematic literature review of cortical ependymomas with a focus on the natural history, clinical characteristics, and clinical outcomes of these lesions as compared to supratentorial ependymomas. Our search revealed 153 unique cases of cortical ependymomas. The mean age on presentation was 21.2 years. Males and females comprised 58.8% (90/153) and 41.2% (63/153) of cases, respectively. The most common presenting symptom was seizure activity occurring in 44.4% of the cohort (68/153). The recently recognized C11orf95-RELA fusion was identified in 13.7% of the cohort (21/153) and 95.5% of cases (21/22) reporting molecular characterization. World Health Organization grades 2 and 3 were reported in 52.3% (79/151) and 47.7% (72/151) of cases, respectively. The frontal lobe was involved in the majority of cases (54.9%, 84/153). Gross total resection was achieved in 80.4% of cases (123/153). Tumor recurrence was identified in 27.7% of cases (39/141). Mean clinical follow-up was 41.3 months. Mean overall survival of patients who expired was 27.4 months whereas mean progression-free survival was 15.0 months. Comparatively, cortical ependymomas with C11orf95-RELA fusions and supratentorial ependymomas with C11orf95 RELA fusions exhibited differing clinical outcomes. Further studies with larger sample sizes are necessary to investigate the significance of RELA fusions on survival in cortical ependymomas and to determine whether cortical ependymomas with C11orf95-RELA fusions should be classified as a distinct entity.

Supratentorial Neurenteric Cysts: Systematic Literature Review and Case Report.

BACKGROUND: Neurenteric cysts (NC) are uncommon congenital lesions with histopathologic properties derived from the gastrointestinal or respiratory tract. They are typically located in the intradural extramedullary compartment but rarely seen in the supratentorial region. The occurrence of supratentorial NCs (S-NC) presents an interesting quandary regarding their embryopathogenesis. METHODS: We present a case report and systematic literature review on S-NCs following PRISMA guidelines. RESULTS: A 57-year-old woman presented with a seizure and paresthesias of the face, hands, and feet. Magnetic resonance imaging showed a right temporo-occipital cystic lesion, which was managed with surgical resection. Histologically, the cyst was type A. The patient was without recurrence at 10 months. Including this case, 88 S-NCs have been reported in the literature. Common presenting symptoms are headaches and seizures. They were mostly treated with craniotomy, preferably with gross total resection, although subtotal resection may be necessary because of adhesions. Resection usually led to symptom improvement (61%). Malignant transformation was seen in 3%. Recurrence was seen in 17%, with a mean time to recurrence of 4.2 years, and was significantly more common after subtotal resection than gross total resection. CONCLUSIONS: If surgically resected, the cyst wall specimen should be sent for pathology review, because of the potential risk for malignancy. If conservatively managed, serial imaging is warranted to track for changes that may indicate transformation. The embryopathogenesis of these rare congenital lesions remains incompletely understood, but the most comprehensive theory involves enteric cell migration to the neuroectoderm during embryogenesis.

Pancreatic Inflammatory Pseudotumor-Like Follicular Dendritic Cell Tumor.

Follicular dendritic cell sarcoma (FDCS) is a rare and underdiagnosed malignant neoplasm which characteristically presents as a solitary, slow-growing mass with no discrete symptoms. Histologically, lymphocytes and spindle cells featuring large nucleoli in a whorled pattern are usually seen. FDCS is classically found in cervical and axillary lymph nodes, with occasional involvement of extranodal sites. Inflammatory pseudotumor-like follicular dendritic cell tumor (IPT-like FDCT) is an uncommon subcategory of this neoplasm, demonstratively linked to the Epstein-Barr virus (EBV). This neoplasm can present similarly to FDCS, but systemic symptoms may be seen. Although, often found in the spleen and occasionally the liver, IPT-like FDCT has not previously been described within the pancreas. Presented, is an IPT-like FDCT of the pancreas and spleen of a 70 years old woman. Histologic features include variably sized geographic suppurative granulomas with chronic inflammatory cells and an atypical spindle cell proliferation with prominent nucleoli. Positivity for CD45 and CD68 in the larger spindled cells points to an inflammatory pseudotumor subtype and co-expression of CD21, CD23, and CD35 were indicative of follicular dendritic differentiation. The pseudotumor additionally demonstrated EBV-encoded RNA (EBER) positivity typical of IPT-like FDCT. Differentiation between inflammatory pseudotumor (IPT) and inflammatory myofibroblastic tumor (IMT) is additionally discussed.