CNS Tumors Flashcards
A child comes in with vision issues. On exam she says that she can only see the middle of the vision field and nothing at the sides. A CT scan shows that she has a supratentorial mass. What kind of tumor does she have and where does it arise from? What kind of features will you see on imaging? Is this a benign tumor?
She has craniopharyngioma which is a tumor that arises from epithelial remnants of Rathke’s pouch. May compress optic chiasm leading to bitemporal hemianopsia. Calcifications are seen. Benign but tends to recur after resection.
What is an ependymoma? Who is it seen in? Which structure does it arise from? What does it present with and what will you find on biopsy?
Malignant tumor of ependymal cells. Children. 4th ventricle, may present with hydrocephalus. Perivascular pseudo rosettes are characteristic finding on histology.
What is a meduloblastoma ? Who is it seen in? What is seen on histology? What is prognosis?
Malignant tumor derived from granular cells of the cerebellum (neuroectoderm). Children. Small round blue cells on histology. Homer Wright rosettes may be present. Poor prognosis. Metastasis via CSF. Drop metastasis to cauda equina.
What is a pilocytic astrocytoma? Who is it seen in? Which structure does it arise from? What is seen on imaging and what will you find on biopsy? What marker is positive?
Benign tumor of astrocytes. Most common CNS tumor in children, usually arises in the cerebellum. Imaging reveals a cystic lesion with a mural nodule. Biopsy shows Rosenthal fibers and eosinophilic granular bodies. Tumor cells are GFAP positive.
What is GFAP and what cells express it?
Glial fibrillary acidic protein which is an intermediate filament protein expressed by the CNS including astrocytes and ependymal cells.
A 28 year old dancer presents to your clinic with seizures. Imaging reveals a calcified tumor in the white matter. What does she have? Which Kobe of the brain is involved? Is it malignant? What would you see on biopsy?
She has oligodendroglyoma which is a malignant tumor of oligodendrocytes. Usually involves frontal lobe. Fried egg appearance of cells on biopsy.
Which cranial nerve is involved in schwannoma and where? How does it present? What markers? Bilateral schwanomas are seen in which tumor?
CN8 at the cerebellopontine angle. Benign. Presents as loss of hearing and tinnitus. Tumor cells are S-100 positive. Bilateral schwanomas are seen in neurofibromatosis type 2.
What is the most common benign CNS tumor in adult women? How does it present? Does the tumor invade other structures? What is seen on imaging? Histology?
Meningioma which is a benign tumor of arachnoid cells. May present as seizures . Tumor does not invade the cortex. Imaging reveals a round mass attached to the dura. Histology shows a whorled pattern. Psammoma bodies may be present.
What is the most common primary malignant CNS tumor? Who is it seen in? Which structure does it arise from? What marker is it positive for? What is seen on histology? Prognosis?
Glioblastoma Multiforme (GBM) which is a malignant high grade tumor of astrocytes. Adults. Arises in cerebral hemisphere, characteristically crosses the corpus callosum (“butterfly” lesion). Characterized by regions of necrosis surrounded by tumor cells pseudo palisading and endothelial cell proliferation. Tumors are GFAP positive. Poor prognosis.
What are the two classifications of cNS tumors? How do metastatic tumors in the brain present? Which region and where do the mets come from?
Metastatic (50%) and primary (50%). Mets present as multiple, well circumscribed lesions at the gray-white junction. Lungs, breast and kidney are common sources.
Where are adult primary tumors located. Which are three common ones?
Supratentorial. GBM, meningioma, schwanoma.
Where are children primary tumors located. Which are three common ones?
Infratentorial. Pilocytic astrocytoma, ependymoma, meduloblastoma. Malignant CNS tumors rarely metastasize.
