Clinical Scorecard: Case Study and Literature Analysis of Primary Diffuse Leptomeningeal Glioblastoma

At a Glance

Key Highlights

• Glioblastoma is the most common malignant primary brain tumor in adults with an incidence of 3 per 100,000 person years.
• Leptomeningeal spread (LMS) of GBM is rare, with primary LMS (at initial diagnosis) being extremely uncommon compared to secondary LMS occurring at recurrence.
• This case reports a 72-year-old woman with GBM presenting exclusively as leptomeningeal disease without a dominant parenchymal lesion, confirmed by imaging and biopsy.

Guideline-Based Recommendations

Diagnosis

• Use MRI brain and whole spine with contrast to identify leptomeningeal enhancement and tumor deposits.
• Perform cerebrospinal fluid (CSF) studies including cytology and flow cytometry to exclude infectious or inflammatory causes, though CSF cytology may be inconclusive.
• Obtain tissue biopsy from leptomeningeal nodules for histopathologic confirmation, including immunohistochemistry and molecular markers.

Management

• Standard GBM treatment includes maximal safe resection followed by radiotherapy with concomitant and adjuvant temozolomide; however, management of primary leptomeningeal GBM is not well established due to rarity.
• Use corticosteroids (e.g., dexamethasone) to manage neurologic dysfunction and edema.
• Consider multidisciplinary neuro-oncology care for individualized treatment planning.

Monitoring & Follow-up

• Monitor neurologic status closely, including sensorium, motor function, and signs of myelopathy.
• Repeat MRI imaging to assess leptomeningeal disease progression or response to therapy.
• Evaluate CSF parameters as clinically indicated.

Risks

• Rapid neurologic decline with poor prognosis; survival ranges from 0.2 to 9.7 months in leptomeningeal GBM.
• Diagnostic challenges due to inconclusive CSF cytology and atypical presentation without parenchymal mass.
• Potential complications from invasive biopsy procedures.

Patient & Prescribing Data

Elderly adult patients with glioblastoma presenting with leptomeningeal disease

Dexamethasone at 8 mg/day was used to manage neurologic symptoms with minimal improvement; standard temozolomide-based chemoradiotherapy remains the backbone of treatment though specific data for primary leptomeningeal GBM is lacking.

Clinical Best Practices

• Maintain high suspicion for leptomeningeal glioblastoma in patients with progressive myelopathy and encephalopathy without a dominant brain mass.
• Use comprehensive neuroimaging including brain and spine MRI with contrast to detect leptomeningeal involvement.
• Pursue tissue diagnosis via biopsy of leptomeningeal nodules when CSF studies are inconclusive.
• Employ corticosteroids judiciously to manage symptoms while planning definitive therapy.
• Coordinate multidisciplinary care involving neurology, neurosurgery, neuro-oncology, and pathology teams.

References

• Incidence and standard therapy of glioblastoma
• Leptomeningeal spread in glioblastoma and survival data
• Primary leptomeningeal glioblastoma case reports and pathology