Radiology · Year 4 · from Radiology

Case 3: Glioblastoma Multiforme

Patient Demographics

  • Age: 58 years
  • Sex: Male

Chief Complaint

Progressive headaches and new-onset seizure

Presenting Symptoms

The patient presents after a witnessed generalized tonic-clonic seizure at home. His wife reports he has complained of worsening headaches over the past 6 weeks, initially attributing them to stress. The headaches are worse in the morning and associated with nausea. She has also noticed personality changes, with him becoming more "flat" and less interested in activities. He had one episode of word-finding difficulty last week that resolved within minutes.

Physical Exam Findings

  • Vital Signs: BP 146/88 mmHg, HR 78 bpm, afebrile
  • GCS: 15 (post-ictal period resolved)
  • Neurological:
  • Subtle right pronator drift
  • Mild expressive aphasia with word-finding pauses
  • Right-sided facial weakness (central pattern)
  • Subtle right-sided neglect
  • Fundoscopic exam: Blurred optic disc margins bilaterally (papilledema)

Imaging Findings and Interpretation

MRI Brain with and without Contrast:

T1-Weighted Pre-Contrast:

  • Large heterogeneous mass in the left frontal lobe
  • Central hypointensity consistent with necrosis
  • Surrounding hypointense vasogenic edema

T2-Weighted/FLAIR:

  • Extensive surrounding T2/FLAIR hyperintensity representing vasogenic edema
  • Edema extends into the corpus callosum
  • Mass effect with effacement of the left frontal horn and 8 mm rightward midline shift

T1-Weighted Post-Gadolinium:

  • Thick, irregular ring enhancement surrounding central necrosis
  • Enhancement is heterogeneous with variable thickness
  • Maximum enhancing tumor dimension: 5.2 x 4.8 cm
  • No additional enhancing lesions to suggest multifocal disease or metastases

Diffusion-Weighted Imaging:

  • Restricted diffusion at the periphery of the mass (high cellularity)
  • Central non-restricted area (necrosis)

MR Perfusion:

  • Elevated relative cerebral blood volume (rCBV) in the enhancing component
  • rCBV ratio 4.2 (compared to contralateral white matter)
  • Consistent with high-grade neoplasm

MR Spectroscopy:

  • Elevated choline peak (increased cell membrane turnover)
  • Decreased N-acetylaspartate (NAA) - neuronal loss
  • Elevated choline/NAA ratio
  • Lipid/lactate peak (necrosis)

Differential Diagnosis:

  1. Glioblastoma multiforme (most likely given imaging characteristics)
  2. Metastatic disease (less likely given single lesion, no primary identified)
  3. Primary CNS lymphoma (typically homogeneous enhancement, crosses midline)
  4. Abscess (would expect more restricted diffusion centrally, rim thinner medially)

Diagnosis

Imaging highly consistent with glioblastoma multiforme (WHO Grade IV astrocytoma); confirmed on surgical pathology with IDH-wildtype, MGMT unmethylated

Management

  1. Immediate:
  • Dexamethasone 10 mg IV then 4 mg q6h for vasogenic edema
  • Levetiracetam for seizure prophylaxis
  • Venous thromboembolism prophylaxis (high-risk tumor)
  1. Tumor Board Discussion:
  • Multidisciplinary review with neurosurgery, neuro-oncology, radiation oncology, neuropathology
  1. Surgical Resection:
  • Maximal safe resection with awake craniotomy and cortical mapping (given proximity to language areas)
  • Gross total resection achieved on post-operative MRI
  1. Adjuvant Treatment:
  • Concurrent temozolomide and radiation therapy (Stupp protocol)
  • Followed by adjuvant temozolomide cycles
  • Consider tumor treating fields (TTFields)
  1. Follow-up Imaging:
  • MRI brain with contrast every 2-3 months to monitor for recurrence
  • Use RANO criteria for response assessment

Radiological Image

Image Description: T1-weighted post-gadolinium MRI demonstrating glioblastoma multiforme with characteristic thick, irregular ring enhancement surrounding a central area of necrosis. Significant surrounding vasogenic edema and mass effect with midline shift are visible.

Source: Wikimedia Commons - "MRI of glioblastoma" URL: https://commons.wikimedia.org/wiki/File:Glioblastoma_multiforme.jpg License: Creative Commons Attribution-Share Alike 3.0 Unported

Learning Points

  1. Subdural vs. Epidural Hematoma: Subdural hematomas are crescent-shaped, cross suture lines, and are typically venous in origin. Epidural hematomas are biconvex (lens-shaped), do not cross sutures, and are usually arterial. This distinction affects prognosis and management urgency.
  1. Acute Stroke Imaging Protocol: Non-contrast CT excludes hemorrhage, CTA identifies large vessel occlusion, and CT perfusion quantifies the ischemic core and penumbra. The mismatch between core and penumbra guides thrombectomy decisions, especially in extended time windows.
  1. Brain Tumor Characterization: Key MRI features distinguishing glioblastoma include irregular thick ring enhancement, central necrosis, vasogenic edema, elevated rCBV on perfusion, and characteristic spectroscopy findings. These help differentiate from metastases, lymphoma, and abscess.
  1. Window Settings in Head CT: Different window and level settings optimize visualization of specific pathology. Brain windows (W:80, L:40) show parenchymal detail, subdural windows (W:150, L:50) detect thin extra-axial collections, and bone windows (W:2000+) evaluate skull fractures.

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