WCTN: World Collaborative Textbook of Neurosurgery

Astrocytoma

General Characteristics

Astrocytomas tend to grow along fiber tracts, versus in brain parenchyma.

Diagnosis

Diagnosis is made largely from adequate MR imaging of the head. Histological studies may confirm diagnosis.

Imaging

When malignancy is suspected, the highest priority for imaging is magnetic resonance. CT imaging may assist in the decision to perform a lumbar puncture.

Lumbar Puncture

Perform only if intracranial pressure is shown to be normal.

Histology of CSF

Tell me what you'd see in CSF

Protein counts of CSF

Which proteins would suggest astrocytoma?

Volume of CSF

Tell me what kind of volume you'd expect.

Grades

Grade I astrocytic tumors: pilocytic astrocytoma, desmoplastic infantile astrocytoma, and subependymal giant cell astrocytoma
Grade II astrocytoma: low-grade, diffuse fibrillary astrocytoma (nuclear atypia and no or rare mitoses)
Grade III astrocytoma: anaplastic astrocytoma (nuclear atypia and marked mitotic activity)
Grade IV astrocytoma: glioblastoma (atypia, mitoses, and microvascular proliferation or necrosis)

Grade I astrocytomas

In general, grade I astrocytomas are benign and resemble nothing more than an increased mass of astrocytes. They grow somewhere...

Pilocytic

Definition

Pilocytic astrocytomas are relatively common. They are well differentiated and are essentially just hyperplastic astrocytes.

Prognosis

As compared to meningiomas, pediatric medulloblastomas and glioblastomas, prognosis for pilocytic astrocytoma is good. Patients are expected to live in xyz% of cases.

Desmoplastic infantile

Desmoplastic are different.

Subependymal giant cell

These are giant.

Grade II astrocytomas

Diffuse fibrillary astrocytoma

In contrast to pilocytic astrocytomas, diffuse fibrillary astrocytomas show nuclear atypia. They usually do not show marked mitosis.

Grade III astrocytomas

Anaplastic

General characteristic of anaplastic neoplasms

Anaplastic astrocytomas show significant growth rates (i.e., mitosis). This makes for poorer prognosis and less predictability in terms of their anatomical location.

Particular considerations in treatment

Due to their high rate of mitotic activity, colchicine and other drugs that prevent microtubule polymerization may be effective.

Grade IV astrocytomas: Glioblastoma

Histological characteristics

As with lower-grade astrocytomas, glioblastomas show hyperplasia, nuclear atypia, and mitotic activity. Additionally, they exhibit microvascular proliferation, making them capable of metastasis.

Prognosis

Glioblastomas are bad mothers. Call your family and spend as much time with them as possible.

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Created by Max Gosey on 2010/06/10 20:47
     
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