What is extra-axial and intra-axial?

Extra-axial is a descriptive term to denote lesions that are external to the brain parenchyma, in contrast to intra-axial which describes lesions within the brain substance.

What is intra-axial and extra-axial brain tumors?

Brain tumors can be intra-axial or extra-axial. The intra-axial tumors are located within brain parenchyma and arise from the brain cells, while the extra-axial tumors are located outside brain parenchyma and arise from structures lining the brain or surrounding it.

What does extra-axial tumor mean?

Extra-axial tumors are lesions, neoplastic and not, which are external to the brain parenchyma and can originate in the skull, meninges, cranial nerves, and brain appendages such as the pituitary gland. Surgery provides a diagnosis and can be the first step in the treatment.

What is extra-axial meningioma?

Meningiomas are extra-axial tumors and represent the most common tumor of the meninges. They are a non-glial neoplasm that originates from the meningocytes or arachnoid cap cells of the meninges and are located anywhere that meninges are found, and in some places where only rest cells are presumed to be located.

Is meningioma Intraaxial or Extraaxial?

Extra-axial brain tumors are the most common adult intracranial neoplasms and encompass a broad spectrum of pathologic subtypes. Meningiomas are the most common extra-axial brain tumor (approximately one-third of all intracranial neoplasms) and typically present as slowly growing dural-based masses.

Is glioblastoma extra-axial?

Glioblastoma should be considered in the differential diagnosis of primary extra-axial mass with atypical and malignant features, especially in elderly patients.

Is the subarachnoid space extra-axial?

Extra-axial fluid is characterized by excessive cerebrospinal fluid in the subarachnoid space, particularly over the frontal lobes.

Are meningioma tumors cancerous?

A meningioma is a type of tumor. It grows in the meninges. These are layers of tissue that cover the brain and spinal cord. These tumors are usually not cancerous (benign).

What are the extra-axial spaces?

The sulci, fissures, basal cisterns and ventricles together form the ‘CSF spaces’, also known as the ‘extra-axial spaces’. CSF is of lower density than the grey or white matter of the brain, and therefore appears darker on CT images.

What is CSF cleft?

The CSF cleft sign in neuroimaging can be used to distinguish an extra-axial lesion from an intra-axial lesion and is typically used in the description of a meningioma. Classically, the cleft was regarded as representing a thin rim of CSF between a tumor and brain parenchyma.