Lecture on Brain Tumors

Overview

• Brain tumors can be categorized into tumors of adulthood and tumors of childhood.
• Important for medical examinations like USMLE.
• Use mnemonics to simplify and remember key facts about each type.

Tumors of Adulthood

1. Glioblastoma Multiforme (GBM)

• Highly malignant and invasive.
• Typically crosses the corpus callosum, creating a "butterfly appearance" in the brain.
• Histology: Pseudopalisading tumor cells, GFAP (glial fibrillary acidic protein) positive.
• Mnemonic: GBM - G for GFAP positive, P for Pseudopalisading, M for Midline/Malignant.

2. Oligodendroglioma

• Histology: Chicken-wire capillary pattern, "Fried egg" appearance of cells, often calcified.
• Mnemonic: Oligo - Chicken-wire (chickens lay eggs), Fried egg appearance, Eggs have calcium (calcification).

3. Meningioma

• Benign, superficial location (arises from meninges).
• Histology: Psammoma bodies, spindle cells.
• Mnemonic: MEN have problems with PSA - P for Psammoma bodies, S for Spindle cells, A for Arachnoid origin.

4. Hemangioblastoma

• Blood vessel origin, EPO producing (can cause polycythemia).
• Associated with von Hippel-Lindau syndrome.
• Mnemonic: Heme (blood) Angio (vessel) Blastoma.

5. Pituitary Adenoma

• Types: Lactotroph (prolactinoma), Somatotroph (e.g., GH, TSH, ACTH producing), Non-functional.
• Symptoms:
  • Prolactinoma: Galactorrhea, Amenorrhea, Gynecomastia, Decreased libido.
  • Somatotroph adenomas produce symptoms based on the hormone secreted (e.g. Gigantism for GH, etc.).
  • Non-functional: Mass effect symptoms like headache, bitemporal hemianopia.
• Mnemonic: Add-enoma - adding hormones or mass effect.

6. Schwannoma

• Located at cerebellopontine angle, affecting CN VII (facial) & CN VIII (vestibulocochlear).
• Histology: S-100 positive.
• Associated with neurofibromatosis type II if bilateral.
• Mnemonic: SCHW - S for S-100, C for Cerebellopontine, H for Hearing, W for Winking.

Tumors of Childhood

1. Pilocytic Astrocytoma

• Histology: Rosenthal fibers, GFAP positive.
• Mnemonic: Houston Astros (Astrocytoma) represented by Drew Rosenhaus (Rosenthal fibers).

2. Medulloblastoma

• Histology: Homer-Wright rosettes.
• Mnemonic: Blast the ball for a homerun (Homer-Wright rosettes).

3. Ependymoma

• Histology: Perivascular pseudorosettes.
• Mnemonic: Forgot mom's birthday, give a pseudo-rosette to make up (Append-a-momma).

4. Craniopharyngioma

• Remnants of Rathke's pouch.
• No mnemonic, just memorize association.

5. Pinealoma

• Causes Parinaud syndrome.
• Mnemonic: P for Pinealoma, P for Parinaud syndrome.

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Additional Notes

• Childhood tumor buzzwords are crucial for exams but less in-depth understanding is required unless pursuing neurology.
• High-yield associations and mnemonics can greatly aid in memorization for exams.
• The lecture emphasizes simplification through mnemonics and understanding key histological features.