CNS Tumors Flashcards
Where are most CNS tumors found?
Over 85% are seen within the brain
Where are most CNS tumors found in adults?
Supratentorial - typically in the cerebrum
Where are most CNS tumors found in children?
Infratentorial - typically in the cerebellum
What is unique about benign and malignant CNS tumors?
Even benign tumors can have fatal outcomes due to their location and often surgical resection is restricted due to anatomical constraints that could leave to damage and loss of function.
Expansile Growth
Sharp border between the tumor and surrounding tissue
Infiltrative Growth
Single tumor cells spread in brain parenchyma and surround normal structures
How frequent is the metastasis of CNS tumors?
VERY rare.
What are some common signs of CNS tumors?
- Headaches
- Nausea and vomiting
- Seizures
- Syncope
What is the most common CNS tumor in adults?
Glioblastoma Multiforme
What is the most common CNS tumor in children?
Pilocytic Astrocytoma
What are the types of gliomas?
- Astrocytoma
- Oligodendroglioma
- Ependymoma
What is seen on microscopy of pilocytic astrocytoma?
Piloid Cells with hair-like processes - biphasic architecture with compact and microcystic areas
What kind of fibers will be seen in pilocytic astrocytoma?
Rosenthal Fibers
Glioblastoma Multiforme
Malignant astrocytoma and is the most common CNS tumor in adults. It can cross the corpus callosum as a butterfly lesion and shows with areas of necrosis
What are the cellular features of glioblastoma multiforme?
- Pseudopalisading cells around necrosis
- Endothelial cell hyperplasia
- GFAP positive
Oligodendroglioma
Malignant tumor of oligodendrocytes that has a better prognosis that others and may present with seizures.
What is a classic finding of oligodendrogliomas on CT?
Intratumoral Calcifications
What is the appearance of oligodendroglioma on histology?
Fried egg appearance of cells with chicken-wire capillary pattern and possible perineuronal/vascular satellitosis.
What are the rosettes seen in medulloblastoma?
Homer-Wright Rosettes - central core of delicate neutrophil fibrils
What are the rosettes seen in retinoblastoma?
Flexner-Wintersteiner Rosettes - cells are arranged around an empty lumen
What are the rosettes seen in ependymoma?
Perivascular Pseudorosette - halo of tumor cells surrounds a blood vessel
AND
True Ependymal Rosette - halo of tumor cells surrounds an empty central lumen
Ependymoma
Arises in the walls of ventricles and central canal of spinal cord and is more frequent in children with the 4th ventricle as the most common site.
Medulloblastoma
Arises from undifferentiated neuroectodermal cells and is malignant and found in children.
What is seen on histology of medulloblastoma?
Sheets of undifferentiated cells with scanty cytoplasm and dark staining nuclei
Meningioma
Arises from arachnoid cells and is benign and seen in adult females and often asymptomatic but can cause seizures.
What are some of the histologic features of meningioma?
- Psammoma bodies
- Whorls
- Fascicles in the fibroblastic variant
Craniopharyngioma
Benign tumor in children that is derived from Rathke’s pouch and can cause visual symptoms and endocrine dysfunction.
What can craniopharyngioma be confused for?
Pituitary Adenoma
What is a symptom in children that raises the possibility of craniopharyngioma?
Presentation of bitemporal hemianopsia
What are some features of craniopharyngioma that can be seen on CT?
Calcifications of the tumor are common
Schwannoma
Benign tumor of Schwann cell origin that is common at the CPA and CN VIII as an acoustic neuroma leading to hearing loss and tinnitus
What does bilateral acoustic neuromas raise suspicion for?
Neurofibromatosis Type-2
What is a marker for Schwannoma?
S100
What are the common sources of metastasis to the CNS?
- Lung
- Breast
- Kidney
A 56‐year‐old man has had headaches and difficulty concentrating for the past 2 months. He then begins to exhibit odd behavior, such as hitting golf‐balls at his neighbors doors and windows. He suffers a grand mal seizure, and is admitted to the hospital. MR imaging of the brain reveals a large mass with extensive necrosis in the left cerebral hemisphere extending across corpus callosum into the right
hemisphere. Which of the following neoplasms is he most likely to have?
A. Meningioma
B. Glioblastoma
C. Medulloblastoma
D. Metastatic adenocarcinoma
B. Glioblastoma
Neurofibromatosis Type-1
Mutation of neurofibromin-GTPase activating protein on Ch17 that leads to a high chance of malignant transformation
What are the symptoms of NFT1?
Neurofibromas, acoustic schwannomas, optic nerve
gliomas, Lisch nodules and café‐au‐lait spots.
– Plexiform neurofibroma is pathognomonic of NF 1
Neurofibromatosis Type-2
Mutation of gene on Ch22 that is a tumor suppressor gene, Merlin, leading to bilateral acoustic Schwannomas and multiple meningiomas
Tuberous Sclerosis
Hamartomatous lesions from mutations in TSC1 and TSC2 (hamartin and tuberin)
What is the triad of tuberous sclerosis?
- Adenoma sebaceum
- Seizures
- Mental retardation
Von Hippel-Landau Disease
VHL tumor suppressor gene on Ch3 is mutated which leads to increased HIF and VEGF leading to growth and tumor formation.
What is VHL disease associated with?
- Hemangioblastoma
- Renal cell carcinoma
Hemangioblastoma
Closely arranged thin‐walled
capillaries with little intervening parenchyma
‐Can produce erythropoietin‐
secondary polycythemia
