Neoplasms

Question 1

Define WHO Grade I lesions.

Answer 1

Grade I lesions generally include tumors with low proliferative potential and may be cured with surgical resection alone. Pilocytic astrocytoma

Question 2

Define WHO Grade II lesions.

Answer 2

Grade II lesions are generally infiltrative and often recur, even with low level proliferation (mitotic activity). Some Grade II lesions may progress to Grade III or IV over time. Treatment is either watchful waiting or external beam cranial radiation. Diffuse astrocytomas, diffuse oligodendrogliomas.

Question 3

Define WHO Grade III lesions.

Answer 3

Grade III lesions have histological evidence of malignancy, including nuclear atypia and brisk mitotic activity. Tx is typically adjuvant radiation and/or chemotherapy. Anaplastic astrocytomas, anaplastic oligodendrogliomas.

Question 4

Define WHO Grade IV lesions.

Answer 4

Grade IV lesions are cytologically malignant, mitotically active, and necrosis-prone. Often associated with rapid pre- and post-operative disease evolution and fatal outcome. Glioblastoma, medulloblastoma.

Question 5

What are the demographics, locations, and tempo/grade of Pilocytic Astrocytoma?

Answer 5

Demographics: Children; Locations: Generally lower brain structures (cerebellum, optic pathway, hypothalamus, thalamus, spinal cord, temporal lobe); Tempo/Grade: WHO I Often presents with Rosenthal fibers (GFAP) and B-RAF fusion. Surgically excisable

Question 6

What are the demographics, locations, and tempo/grade of Diffuse Astrocytoma?

Answer 6

Demographics: Adults (30s-40s); Locations: Cerebral hemispheres; Tempo/Grade: WHO II, Not surgically excisable.

Question 7

What are the demographics, locations, and tempo/grade of Oligodendroglioma?

Answer 7

Demo: Adults; Location: Cerebral white matter; Tempo/Grade: WHO II; Associated with LOH 1p/19q

Question 8

What are the demographics, locations, and tempo/grade of Anaplastic Astrocytoma?

Answer 8

Demo: Adults; Location: Cerebral Hemispheres; Tempo/Grade: WHO III; Greater mitotic activity that grade II, IDH mutations, TP53 mutation or 17p loss.

Question 9

What are the demographics, locations, and tempo/grade of Anaplastic Oligodendroglioma

Answer 9

Demo: Adults; Location: Supratentorial region; Tempo/Grade: WHO III; AO lesions that have the LOH 1p/19q have a better prognosis and respond better to radiation and chemotherapy.

Question 10

What are the demographics, locations, and tempo/grade of an Ependymoma?

Answer 10

Demo: Children/Teens in 4th ventricle, Adults in Spinal Cord; Tempo/Grade: WHO II

Question 11

What are the demographics, locations, and tempo/grade of Choroid Plexus Papilloma?

Answer 11

Demo: Children; Location: Lateral Ventricles; Tempo/Grade: WHO I

Question 12

What are the demographics, locations, and tempo/grade of Primary Glioblastoma?

Answer 12

Demo: Adult (~62); Location: Cerebral hemispheres; Tempo/Grade: WHO IV; Arises spontaneously with 10q loss, PTEN mutation, EGFR amplification…

Question 13

What are the demographics, locations, and tempo/grade of Secondary Glioblastoma?

Answer 13

Demo: Adult (~45); Location: Cerebral Hemispheres; Tempo/Grade: WHO IV; Arises due to the progression of Anaplastic astrocytoma or oligodendrocytoma w/ 9p and 10q loss.

Question 14

What are the demographics, locations, and tempo/grade of Medulloblastoma?

Answer 14

Demo: Children; Location: Cerebellum; Tempo/Grade: WHO IV

Question 15

What are the demographics, locations, and tempo/grade of Meningiomas?

Answer 15

Demo: Adults (Women in the 50s); Location: Meniniges, not neural/glial cells; Tempo/Grade: WHO I. Highly responsive to surgical resection.

Question 16

What are the demographics, locations, and tempo/grade of Schwannomas?

Answer 16

Demo: ???; Location: Frequently on CN8 (Acoustic nerve, Acoustic Neuroma); Tempo/Grade: ???

Question 17

Which tumor types tend to spread through the CSF?

Answer 17

Ependymomas, particularly childhood tumors in the fourth ventricle, and medulloblastomas.

Question 18

How does the histological typing and grading of tumors correlate with prognosis and affect treatment?

Answer 18

WHO grades essentially classify tumors by their rate of proliferation. The higher the grade, the more mitotic activity present in the tumor. The greater the mitotic activity, the more severe the treatment and the poorer the prognosis.