Atypical meningioma


  • A 22 years old man
  • Presented with sudden onset of generalized tonic clonic fit. He had no history of childhood seizure.
  • He had localized headaches and a skull swelling noted few months before the fitting episode.
  • No loss of appetite or loss of weight
Plain CT brain in axial plane; (A) soft tissue and (B) bone windows.

CT findings:

  • There is a destructive lytic lesion of the right frontal bone (white arrow) with surrounding soft tissue swelling (red arrow).
  • Small foci of calcification seen in the adjacent brain parenchyma.
  • Associated subtle effacement of adjacent brain parenchyma
MRI of brain in sagittal plane; (A) T1WI and (B) T1+Gadolinium
MRI brain in coronal plane; (C) T1+gadolinium and (D) T2FLAIR

MRI findings:

  • A lobulated broad-based lesion at right frontal lobe (white arrows)
  • It is isointense on T1, slightly hyperintense on T2 and homgenously enhances post contrast
  • Dural tail seen
  • No central necrosis seen
  • Associated marked perileseional oedema
  • Bony and scalp infiltration as noted on CT scan

HPE findings:

  • Subcutaneous tumour: highly cellular tumour cells in sheet-like pattern. Cells moderately pleomorphic.
  • Brain tumours: 30 mm in aggregate diameter. Cut section shows whitish appearance. Microscopically shows highly cellular tumour cells arranged in sheet-like pattern. Tumour cells display moderate pleomorphism with large oval nucleus with central clearing and indistinct cytoplasmic borders. Some showed prominent nucleoli. Mitosis occasionally seen (1/10hpf). Tumour necrosis seen. Surrounding tissue is infiltrated by chronic inflammatory cells.
  • Immunohistochemical stain shows malignant cells positive for EMA, ki-67 with proliferation index 10%.

Diagnosis: Atypical meningioma with skull infiltration, WHO Grade II.

Discussion: Atypical meningioma

  • Most meningiomas are benign and classified as grade I according to World Health Organization (WHO) standards
  • Atypical meningiomas account for between 4.7 and 7.2% of all meningiomas
  • Malignant meningiomas are less common, comprising between 1.0 and 2.8%
  • It should be noted that epidemiology, clinical presentation, and radiographic features do not reliably distinguish these different types of meningiomas.
  • Generally, atypical meningiomas grow faster, have more heterogeneous/aggressive imaging appearances, and have a tendency to recur early.
  • The presence of vasogenic edema in adjacent brain parenchyma is not a predictor of atypical or anaplastic histology
  • The five-year recurrence rate is significantly higher (41%) than that seen in grade I (benign) meningiomas (12%)

Progress of patient:

  • Patient had operation done
MRI brain coronal plane, T2FLAIR weighted images


  • 2 years later patient presented with acute shortness of breath and noted to have massive pleural effusion with multiple lung metastasis
  • Pleural biopsy done concluded as morphological, immunohistochemical and clinical presentation are compatible with metastatic meningioma


Author: radhianahassan