Specific clinical and radiological features may identify risk for leptomeningeal dissemination in oligodendrogliomaRisk Markers Linked to Spread of Oligodendroglioma in Spinal Fluid

Frontiers in Medicine Published June 16, 2026 DOI ↗ Editorial oversight: Dr. Julia Lee, PhD · Oncology, Genomics & Drug Development

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Key Takeaway

Note that WHO grade 3 histology and high Ki-67 index are associated with leptomeningeal dissemination in oligodendroglioma.

This scoping review synthesizes data from 15 studies involving 48 patients with oligodendroglioma (ODG) to identify clinical, radiological, surgical, and histo-molecular risk markers for leptomeningeal dissemination (LMD). The authors highlight that LMD is associated with a poor prognosis in this patient population.

Key findings include a high prevalence of WHO grade 3 ODG among patients with LMD (85.7%). Additionally, associations were noted between LMD and specific markers: Ki-67 index of $≥$15% (85.7%), contrast enhancement on MRI (75%), and surgical entry into the ventricles (50%). The median survival after LMD was reported as 9.9 months (range 1.8 to 67.7).

The authors note that while features such as grade 3 histology, ventricular involvement, high Ki-67 index, and contrast enhancement are identified as potential risk markers, they are not established causal predictors due to the observational nature of the source data. The evidence is characterized by low certainty because of the small number of studies (15) and total patients (48).

Clinicians may consider these factors when assessing risk for LMD in patients with oligodendroglioma, though current findings are preliminary and limited by sample size.

This review looked at 48 patients with oligodendroglioma (ODG) who experienced leptomeningeal dissemination, which is when the cancer spreads to the membranes surrounding the brain and spinal cord. Because this type of spread is often linked to a poorer outlook for patients, identifying risk markers is very important.

The review found several factors associated with this spread. These include having a WHO grade 3 tumor, high Ki-67 index levels (15% or higher), and contrast enhancement on MRI scans. Other potential indicators included surgery that entered the ventricles and specific tumor features. The average age of patients at the time of diagnosis was about 43 years.

It is important to note that this study involved a small number of cases across only 15 reports, which means the evidence is not yet definitive. While these markers are linked to the spread of the disease, they are not proven causes. Patients should speak with their medical team to understand how these specific findings apply to their personal diagnosis and treatment plan.

What this means for you:

Certain factors like high Ki-67 levels may indicate a higher risk of tumor spread in some patients.

Common questions

What are the risk factors for tumor spread in these patients?

The review identified several potential risk markers for leptomeningeal dissemination. These include a WHO grade 3 histology, a Ki-67 index of 15% or higher, and contrast enhancement on MRI scans. Other factors like surgical entry into the ventricles were also noted as indicators that may help identify patients at risk.

Who was included in this study?

The review looked at 48 patients who had oligodendroglioma and experienced leptomeningeal dissemination. The average age of these patients at the time of diagnosis was 43.1 years, and there was a notable male predominance, with men outnumbering women by a ratio of 2.4 to 1.

How certain are these findings?

The certainty of these results is currently low because the study only included 15 reports and 48 total patients. While these markers show a link to the spread of the tumor, they are not yet established as confirmed predictors. You should discuss these specific findings with your doctor.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedJun 2026

View Original Abstract ↓

IntroductionOligodendrogliomas (ODGs) are IDH-mutated gliomas with 1p/19q co-deletion, typically associated with better outcomes than astrocytomas. Symptomatic leptomeningeal dissemination (LMD) is exceptionally rare, and predictors of its occurrence remain poorly defined. This scoping review aimed to synthesize the available literature on LMD in ODG and identify potential clinical, radiological, surgical, and histo-molecular risk markers.MethodsPubMed/MEDLINE and Embase were systematically searched for studies reporting cases of ODG with LMD. Extracted data included demographics, tumor features, imaging, treatment, molecular markers, and outcomes. Findings were descriptively summarized. An illustrative institutional case was also reviewed.ResultsOf 1719 records screened, 15 studies met inclusion, comprising 48 patients. The mean age at LMD diagnosis was 43.1 years, with male predominance (M: F = 2.4:1). Most patients (39 of 41 patients [85.7%]) had WHO grade 3 ODG at LMD diagnosis. When explicitly stated, LMD was associated with surgical entry into the ventricles (2 of 4 patients [50%]), a Ki-67 index of ≥15% (6 of 7 patients [85.7%]), and contrast enhancement on MRI (4 of 8 patients [75%]). The median time from ODG diagnosis to LMD was 35 months (range 0–274 months). Median survival after LMD was 9.9 months (range 1.8-67.7). Our case reflected these patterns, with 14 years of stable disease followed by rapid decline after LMD onset. Treatments included chemotherapy (23 of 39 patients [58.9%]), radiotherapy (14 of 39 patients [35.9%]), and surgery (12 of 40 patients [30%]), with uncertain benefit.DiscussionLMD in ODG is rare but associated with poor prognosis. Features such as grade 3 histology, ventricular involvement, surgical entry into ventricles, contrast enhancement, and high Ki-67 may indicate potential risk markers. These findings support long-term whole-neuroaxis MRI surveillance in selected patients.

Specific clinical and radiological features may identify risk for leptomeningeal dissemination in oligodendrogliomaRisk Markers Linked to Spread of Oligodendroglioma in Spinal Fluid

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Specific clinical and radiological features may identify risk for leptomeningeal dissemination in oligodendrogliomaRisk Markers Linked to Spread of Oligodendroglioma in Spinal Fluid

Common questions

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Clinical research that matters. Delivered to your inbox.

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