Neurology: Case of the Month

Test Yourself — Patient 11

Astrocytic Tumors of the CNS

  1. Which following statement is TRUE about a pilocytic astrocytoma (WHO grade 1):
    • [ A ] It is the most frequent brain tumor seen in adults.
    • [ B ] It has a peak incidence between the ages 45 to 60.
    • [ C ] It tends to be more midline in origin.
    • [ D ] It is infiltrative in nature.
  2. All of the following would be typical of a gemistocytic astrocytoma EXCEPT:
    • [ A ] Gemistocytic astrocytoma has extensive mitotic activity and vascularity.
    • [ B ] Gemistocytic astrocytoma is homogenous in appearance with occasional cysts.
    • [ C ] Gemistocytic astrocytoma is classified as a low grade astrocytoma (WHO grade 2) and occurs predominantly in the cerebral hemispheres.
    • [ D ] Gemistocytic astrocytoma is composed predominantly of gemistocytic astrocytes which are eosinophilic cells with a plump and glassy appearance.
  3. The following statement is TRUE regarding imaging studies of astrocytomas:
    • [ A ] Low grade astrocytomas typically show increased signal on T1 and decreased signal on T2 MRI.
    • [ B ] Low grade astrocytomas normally show very little enhancement with contrast.
    • [ C ] Anaplastic astrocytomas (WHO grade 3) usually have distinct borders with little or no associated edema.
    • [ D ] In glioblastoma multiforme (WHO grade 4), due to surrounding edema, the cystic areas can no longer be visualized.
  4. All of the following are TRUE regarding treatment for astrocytomas EXCEPT:
    • [ A ] Brachytherapy is the placement of radioactive isotopes directly into the tumor using radioactive seeds.
    • [ B ] Chemotherapy such as BCNU has been used as therapy for glioblastomas.
    • [ C ] In some tumors, like juvenile pilocytic astrocytomas, surgical resection may produce complete cures.
    • [ D ] Antiangiogenesis consists of using a delivery system or a vector to introduce a gene product into cells.
  5. All of the following statements are TRUE regarding astrocytomas EXCEPT:
    • [ A ] Metastasis from sites outside the CNS account for the majority of CNS neoplasms in adults.
    • [ B ] Primary neoplasms of CNS are more common in children.
    • [ C ] Gliomas represent about 5 percent of the primary neoplasms.
    • [ D ] Astrocytomas have been found to be associated with several gene alterations, including amplification of oncogenes and mutations or deletion in several tumor suppressor genes.

 

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