Pathology V Flashcards
Where are pilocytic (low grade) astrocytomas usually found?
In the posterior fossa (e.g. cerebellum) and may be supratentorial. Tumors are usually well circumscribed and benign with good prognosis (p.448)
What type of staining is characteristically positive in pilocytic astrocytomas?
GFAP positive (p.448)
What characterizes histology of pilocytic astrocytoma tumors?
Rosenthal fibers- eosinophilic, corkscrew fibers. Cystic and solid on gross appearance (p.448)
What are medulloblastomas?
Highly malignant cerebellar childhood tumors; a form of neuroectodermal tumor; radiosensitive (p.448)
What complication are often associated with medulloblastomas?
Compression of the 4th ventricle causing hydrocephaulus; drop metastes in spinal cord (p.448)
What characterizes histology of medulloblastomas?
Homer-Wright rosettes; solid (gross) small blue cells (histology) (p.448)
Where are ependyomas most commonly found?
4th ventricle of children (p.448)
From what type of cells are ependymomas typically derived?
Ependymal cells (p.448)
What complications are associated with ependyomas?
May cause hydrocephalus (p.448)
What is the prognosis for a patient with an ependymoma?
Poor prognosis (p.448)
What characterizes histology of ependymoma?
Perivascular pseudorosettes. Rod-shaped blepharoplasts (basal ciliary bodies) found near nucleus (p.448)
Where are hemangioblastomas most typically located?
Cerebellum (p.448)
What condition is associated with hemangioblastoma?
von Hippel Lindau syndrome when found with retinal angiomas (p.448)
What are hemangioblastomas characterized when they produce EPO?
Secondary polycythemia (p.448)
What characterizes histology of hemangioblastoma?
Foamy cells and high vascularity (p.448)
What is a craniopharyngioma?
A benign childhood tumor that is often confused with pituitary adenoma (p.448)
Where are craniopharyngiomas most commonly located?
Most common childhood supratentorial tumors (p.448)
What two types of tumors most commonly cause bitemporal hemianopia?
Pituitary adenomas (adults), craniopharyngiomas (children) (p.448)
From where are craniopharyngiomas derived?
Remnants of Rathke’s pouch (p.448)
What histologic findings are characteristic of craniopharyngiomas?
Calcification common (tooth enamel-like) (p.448)
Name the four types of herniation syndromes.
Cingulate (subfalcine); Downward transtenorital (central); Uncal; Cerebellar tonsillar (p.448)
Where does cingulate (subfalcine) herniation occur?
Under the falx cerebri (p.448)
What structure may be compressed by cingulate (subfalcine) herniation?
Anterior cerebral artery (p.448)
In what lobe is the uncus present?
Medial temporal lobe (p.448)
Where does herniation of the cerebellar tonsils most commonly occur?
Into the foramen magnum (p.448)
