Spinal metastasis of gliosarcoma: Array-based comparative genomic hybridization for confirmation of metastatic spread

Natural history of spinal cord metastasis from brain glioblastomas

BACKGROUND AND OBJECTIVES

Spinal cord metastasis arising from an intracranial glioblastoma is a rare and late event during the natural course of the disease. These pathological entities remain poorly characterized. This study aimed to identify and investigate the timeline, clinical and imaging findings, and prognostic factors of spinal cord metastasis from a glioblastoma.

METHODS

Consecutive histopathological cases of spinal cord metastasis from glioblastomas in adults entered in the French nationwide database between January 2004 and 2016 were screened.

RESULTS

Overall, 14 adult patients with a brain glioblastoma (median age 55.2 years) and harboring a spinal cord metastasis were included. The median overall survival as 16.0 months (range, 9.8-22.2). The median spinal cord Metastasis Free Survival (time interval between the glioblastoma diagnosis and the spinal cord metastasis diagnosis) was 13.6 months (range, 0.0-27.9). The occurrence of a spinal cord metastasis diagnosis greatly impacted neurological status: 57.2% of patients were not ambulatory, which contributed to dramatically decreased Karnofsky Performance Status (KPS) scores (12/14, 85.7% with a KPS score ≤ 70). The median overall survival following spinal cord metastasis was 3.3 months (range, 1.3-5.3). Patients with a cerebral ventricle effraction during the initial brain surgery had a shorter spinal cord Metastasis Free Survival (6.6 vs 18.3 months, p = 0.023). Out of the 14 patients, eleven (78.6%) had a brain IDH-wildtype glioblastoma.

CONCLUSIONS

Spinal cord metastasis from a brain IDH-wildtype glioblastoma has a poor prognosis. Spinal MRI can be proposed during the follow-up of glioblastoma patients especially those who have benefited from cerebral surgical resection with opening of the cerebral ventricles.

Hypermutated phenotype in gliosarcoma of the spinal cord

Gliosarcoma is a variant of glioblastoma with equally poor prognosis and characterized by mixed glial and mesenchymal pathology. Metastasis is not uncommon but the involvement of the spinal cord is rare, and comprehensive genetic characterization of spinal gliosarcoma is lacking. We describe a patient initially diagnosed with a low-grade brain glioma via biopsy, followed by adjuvant radiation and temozolomide treatment. Nearly 2 years after diagnosis, she developed neurological deficits from an intradural, extramedullary tumor anterior to the spinal cord at T4, which was resected and diagnosed as gliosarcoma. Whole-exome sequencing (WES) of this tumor revealed a hypermutated phenotype, characterized by somatic mutations in key DNA mismatch repair (MMR) pathway genes, an abundance of C>T transitions within the identified somatic single nucleotide variations, and microsatellite stability, together consistent with temozolomide-mediated hypermutagenesis. This is the first report of a hypermutator phenotype in gliosarcoma, which may represent a novel genomic mechanism of progression from lower grade glioma.

Extensive Leptomeningeal Intracranial and Spinal Metastases in a Patient with a Supratentorial Glioblastoma Multiforme, IDH-Wildtype

BACKGROUND

Glioblastoma multiforme (GBM) is usually characterized by diffuse, infiltrative growth and local tumor progression. Extensive leptomeningeal metastases are rarely observed. It is unclear which GBMs are prone to this specific growth pattern and progression, and standardized salvage treatment protocols are unavailable.

CASE DESCRIPTION

In a 45-year-old man without focal neurologic deficit, a right temporal GBM, IDH-wildtype (biomarkers MGMT promoter methylation negative, Ki-67 proliferation rate 70%) was diagnosed. Gross tumor resection followed by concomitant and adjuvant radiotherapy and chemotherapy with temozolomide was performed. Routine follow-up imaging 8 months later showed a right parietal meningeal tumor. Resection confirmed a distant GBM, and next-generation sequencing revealed high tumor mutational burden, high-frequency microsatellite instability, and a pharmacologically targetable KIT mutation. Complete neuraxis imaging revealed multiple contrast-enhancing tumors in the craniocervical junction and levels C7, Th8-Th11, and S1. The craniocervical tumors and the cervical spine from C1-C2 were irradiated as palliative care, and second-line combined chemotherapy and antiangiogenic therapy with irinotecan and bevacizumab was initiated, which was later changed to an immune-checkpoint blockade with pembrolizumab in combination with bevacizumab owing to tumor progression. Tumor growth was slowed, but the patient eventually developed a progressive paraparesis. Subsequent KIT-targeting tyrosine kinase inhibitor therapy with imatinib was administered for a short time. The patient died 13.8 months after initial diagnosis.

CONCLUSIONS

High-risk genetic profiles for GBMs prone to develop extensive leptomeningeal metastases need to be identified. Guidelines on preemptive, complete neuraxis imaging in certain patients with GBM as well as treatment guidelines need to be developed.

Gliosarcoma with neuroaxis metastases

Gliosarcomas are rare tumours of the central nervous system, with a well-known capacity for metastasis. When they metastasise, the dissemination occurs more frequently via the haematogenous route to extraneural sites. Metastasis-spread through the cerebrospinal fluid is extremely rare. We present the case of a 58-year-old man who underwent a gross total resection of a lesion in the left temporal lobe. The histological findings revealed a gliosarcoma and the patient received radiotherapy followed by chemotherapy. Seven months after surgery, while the patient remained neurologically intact, brain and spinal cord MRI revealed tumour recurrence and neuroaxis metastases through the traffic routes of the cerebrospinal fluid. The patient died 8 months after the diagnosis. A PubMed search regarding metastatic gliosarcoma up to June 2015 was also carried out. To the best of our knowledge, this is the first case report of gliosarcoma metastases to the brain and spinal cord leptomeninges.

Diagnosis and Management of Spinal Metastasis of Glioblastoma

Background: When patients with cranial glioblastoma develop weakness, a rare differential diagnosis is spinal metastases. Methods: Chart and literature reviews were performed. Results: The reported patient had delayed onset spinal drop metastasis that was only detected by magnetic resonance imaging (MRI). A 48-year-old patient had supratentorial glioblastoma, treated with radiotherapy (RT) and concurrent temozolomide followed by six cycles of adjuvant temozolomide. Four years after completion of all treatments (62 months from initial presentation), he developed low backache and weakness in both legs. Positron emission tomography/computed tomography scans demonstrated intracranial recurrence only. Spinal drop metastases were detected only by MRI scan. Local spinal RT 40 Gy in 20 fractions with concurrent and maintenance temozolomide were given. Because of disease progression after nine cycles of temozolomide, systemic therapy was changed to bevacizumab, which greatly improved his symptoms for 4 months before deterioration of mental status. He is still alive with disease at 22 months after diagnosis of spinal metastases (84 months from initial glioblastoma diagnosis). Conclusions: MRI is the diagnostic imaging of choice for spinal metastases. This illustrative case of delayed-onset spinal metastases shows unusual slow progression. Local RT, temozolomide, and targeted therapy may improve survival. This illustrative case is the first report of bevacizumab as a second-line therapy in drop metastasis of glioblastoma.