Post-operative meningeal thickening seen on magnetic resonance imaging

Posterior fossa tumors are relatively common in children, and the meningeal dissemination of these tumors is well established in the literature. Although leptomeningeal dissemination is more common in high-grade tumors, even low-grade tumors can generate meningeal metastases. In this case report, we would like to discuss the importance of leptomeningeal dissemination assessment of posterior fossa tumors in children, in the preoperative period, through the entire neuroaxis magnetic resonance imaging (MRI). This is important since transient meningeal thickening is very common in the postoperative periods of neurosurgical patients, and can be found for up to 5 or 6 years after surgery, causing these patients to undergo prolonged follow-ups and repeated MRIs and lumbar punctures.

Adenoid cystic carcinoma with a leptomeningeal dissemination in a ‘wash’ pattern

A 39-year-old woman was referred to the neurology department due to headache, instability and difficulty walking for 5 months. Several ancillary tests were performed. The blood test showed leucocytosis and the cerebrospinal fluid revealed an increased total protein and glucose consumption. Other infections or autoimmune causes were excluded. The MRI showed non-specific brain and spinal cord lesions. Given the findings described, a differential diagnosis between granulomatous meningoencephalitis and primary tumour or metastasis was proposed. Empirical treatment with tuberculostatic agents and corticosteroids was started. The neurological state of the patient worsened, she fell into a non-responsive coma and died in few days. The clinical autopsy performed revealed an adenoid cystic carcinoma with involvement of the central nervous system that developed leptomeningeal dissemination along the spinal cord in a fluid ‘wash’ pattern.

Leptomeningeal Dissemination of Low-Grade Neuroepithelial Tumor with FGFR1_TACC1 Fusion with Clinical and Radiographic Response to Pazopanib and Topotecan

<b><i>Introduction:</i></b> Low-grade neuroepithelial tumors are a heterogeneous group of central nervous system tumors that are generally indolent in nature but in rare instances can progress to include leptomeningeal dissemination. <b><i>Case Presentation:</i></b> We present a case of a patient with a low-grade neuroepithelial tumor of indeterminate type with symptomatic leptomeningeal dissemination despite 3 chemotherapy regimens and radiotherapy. Somatic targetable mutation testing showed an FGFR1_TACC1 fusion. Therapy with pazopanib/topotecan was initiated, and disease stabilization was achieved. He received pazopanib/topotecan for a total of 2 years and is now &#x3e;2 years from completion of treatment and continues to do well with no evidence of disease. <b><i>Discussion:</i></b> This case highlights the utility of targetable mutation testing in therapeutic decision-making and the novel use of systemic pazopanib/topotecan therapy for refractory low-grade neuroepithelial tumor within the context of this clinical situation and specific mutation profile.

Spinal Cord Diffuse Leptomeningeal Glioneuronal Tumor Presenting without Leptomeningeal Dissemination

<b><i>Background and Importance:</i></b> Diffuse leptomeningeal glioneuronal tumor (DLGNT) represents a provisional entity in the 2016 World Health Organization classification of tumors; it is characterized by a widespread leptomeningeal growth and oligodendroglial-like cytology. To this day, 4 pediatric patients have been reported to present with an isolated spinal cord tumor in the absence of leptomeningeal dissemination. Gross total resection (GTR) was achieved in only 1 patient. We present the clinical and technical nuances of this unique type of tumor, as well as the second reported case of GTR in a patient with DLGNT. <b><i>Clinical Presentation:</i></b> A 4-year-old boy presented to the emergency department after an episode of flaccid paralysis of bilateral lower extremities. MRI showed an intramedullary spinal cord tumor centered at T8. The patient was taken to the operative room, where a laminectomy and tumor resection were performed; cystic and solid tumor components were identified. Pathology report was consistent with DLGNT. After achieving GTR, patient is free of recurrence after a 15-month follow-up. <b><i>Conclusion:</i></b> No standard treatment for DLGNT has been identified. Current literature report surgery and chemotherapy with variable success rates. DLGNT presenting as an isolated intramedullary tumor is an uncommon condition which progression appears to be halted when treated promptly. Identifying solid and cystic components of this tumor is crucial for achieving GTR.

LMD-12. Ubiquitin Conjugating Enzymes promote leptomeningeal dissemination and decrease survival in patients with brain metastatic disease

The dissemination of cancer cells to the brain parenchyma (brain metastases - BMs) and to the leptomeninges (leptomeningeal dissemination – LD) are a late-stage complication of systemic cancers, with a poor survival. Despite advances in radiation and chemotherapy, including intrathecal administration of anticancer agents, these forms of advanced cancer are incurable. Therefore, there is an unmet clinical need for novel effective therapies that target both parenchymal and leptomeningeal disease. We analysed the transcriptomic profile of BMs from patients with diverse primary tumors, treated at CHULN, to identify genetic drivers of cancer cell dissemination to the brain and potential novel targets for therapy. The most differentially expressed gene codifies a ubiquitin conjugating enzyme (UCE). UCE levels were evaluated in tissue microarrays of BMs from an independent cohort of patients and correlated with clinical data. UCE functional role was assessed in vitro and in vivo using modulated lung and breast cancer cell lines. A high-throughput drug screening was performed to find UCE-targeting compounds. High protein levels of the UCE were associated with decreased survival in patients with BMs, independently of the primary tumor origin. High levels of UCE led to increased migration and invasion abilities in cancer cell lines in vitro, with no effect in proliferation. In vivo, high levels of UCE increased leptomeningeal dissemination and decreased survival in orthotopic models of breast cancer BMs. Leptomeningeal disease promoted by UCE was prevented by oral administration of inhibitor A, identified in our high-throughput drug screening. In conclusion, we have identified UCE as a prognostic marker in patients with BMs from different primary tumors. In orthotopic mouse models of the disease, UCE led to a worse survival and promoted leptomeningeal dissemination. Strikingly, this aggressive disease phenotype was prevented by oral therapy with inhibitor A.

Optic Nerve Pilocytic Astrocytoma With Leptomeningeal Dissemination – Case Report

"Pilocytic astrocytoma is the most frequent type of brain tumor diagnosed during childhood. It originates from midline structures and is associated with good prognosis, with an estimated survival rate higher than 95%. We presented the case of a male patient diagnosed at the age of 6 with pilocytic astrocytoma located in the right optic nerve with associated chiasm infiltration. Incomplete resection of the tumoral process was performed, without any additional therapy, as association of chemotherapy or radiotherapy is still controversial among specialists. The patient had an unpredictable severe evolution of the disease, with associated leptomeningeal dissemination and extreme worsening of neurological and endocrinologic status. Six years after diagnosis, despite complex medical efforts the patient died. This article raises awareness of leptomeningeal dissemination risk, a rare evolution in cases of pilocytic astrocytoma. Early diagnosis, complete tumoral resection, tumor location and careful long-term follow up are key factors for long-term survival. "