BRAIN TUMORS Flashcards
are the most common type of intracranial tumors in adults
Brain metastases of carcinomas (e.g., lung, melanoma, renal)
_________ are benign, slow-growing tumors that arise from arachnoid cells. They are usually asymptomatic and found incidentally on imaging.
Meningiomas
___________________________are benign tumors that arise from the Schwann cells of peripheral nerves. They are usually located in the cerebellopontine angle (infratentorial) because they primarily arise within the vestibular portion of the vestibulocochlear nerve (CN VIII). Symptoms depend on the nerves affected by the tumor (e.g., dizziness, hearing loss, facial nerve palsy)
Schwannoma
_____________________-are highly malignant, rapidly progressive brain tumors that commonly manifest with nonspecific neurological symptoms. They are typically located in the white matter of the cerebral hemispheres (e.g., left temporal lobe), although they can cross the midline (butterfly). Gross hemorrhage, central necrosis, and microvascular proliferation are further pathological characteristics. On MRI, the tumor would appear as a ring-enhancing mass due to central necrosis. This kind of tumor is derived from from astrocytes.
Glioblastoma
___________________are benign, slow-growing, highly vascularized tumors. They are typically located in the cerebellum (infratentorial), which is why symptoms often include cerebellar defects (e.g., ataxia). Features of increased intracranial pressure (e.g., headaches, vomiting) may occur if the tumor compresses the fourth ventricle. On gross pathological examination, these tumors appear red due to their high vascularity and they are often located within a cyst.
hemangioblastoma
_ ________________are slow-growing tumors that arise from oligodendrocytes. While these tumors can manifest with the nonspecific neurological symptoms seen here, the disease course of this tumor is often much less rapid. Additionally, they are usually found in the frontal lobe. On gross pathological examination, they may show areas of necrosis.
Oligodendrogliomas
tumor derived from astrocytes.
Glioblastoma
This kind of tumor can occur sporadically or as a manifestation of Von Hippel-Lindau
Hemangioblastoma
A disease resulting from the deletion of the VHL gene on chromosome 3, which encodes a tumor suppressor. Subsequently, activity of hypoxia inducible factor 1a is increased. VHL is associated with hemangioblastomas, bilateral renal cell carcinoma, pheochromocytoma, and renal/pancreatic cysts.
Von Hippel-Lindau
These are commonly located in the infratentorial region, may present with features of increased intracranial pressure (e.g., headache, vomiting, blurred vision, papilledema). However, they are not associated with retinal vascular changes. Moreover, this type of tumor most commonly develops in early childhood. Histology typically shows perivascular pseudorosettes and rod-shaped blepharoplasts. This kind fo tumor is associated with Neurofibromatosis type 2.
Ependymoma
The histopathologic findings of a cystic mass filled with dark, oily fluid (“motor oil-like”) confirm this diagnosis.
Craniopharyngioma
_______________________________are derived from remnants of the Rathke pouch, which is an ectodermal outpouching of the pharyngeal roof that develops into the anterior pituitary gland. Compression of the optic chiasm by this tumor causes bitemporal hemianopsia and possibly, clumsiness or frequent tripping due to the visual field defect. Destruction of the posterior pituitary by the tumor results in central diabetes insipidus, which may present as increased urinary frequency.
craniopharyngioma
Medulloblastomas, which are the most common malignant brain tumor in children, originate from the _____________________ and can cause clumsiness, frequent falls, and urinary symptoms
primitive neuroectoderm
_____________________, which are the most common malignant brain tumor in children, originate from the primitive neuroectoderm and can cause clumsiness, frequent falls, and urinary symptoms
Medulloblastomas
Homer Wright rosettes are associated with what?
medulloblastoma, primitive neuroectodermal tumors, neuroblastoma, pineoblastoma
Arachnoid cells give rise to what tumor?
meningioma
____________________are characterized on histopathology by layers of densely packed syncytial tumor cells, often arranged in whorls, interspersed spindle cells, and psammoma bodies.
meningiomas
____________________arise from astroglial cells.
Astrocytomas
S-100
S-100 is an immunohistochemical marker that identifies cells of neural crest origin. Tumors of neural crest origin that stain positive for S-100 include pheochromocytoma (from chromaffin cells), melanoma, schwannoma, and Langerhans cell histiocytosis.
100 swans a swimming
Synaptophysin
Synaptophysin is an immunohistochemical marker that identifies tumors derived from neuronal cells, e.g., neuroendocrine cells, which contain numerous synaptic vesicles. Tumors that stain positive with synaptophysin include neurocytomas, medulloblastomas, small cell carcinomas of the lung, and carcinoid tumors. Neurons also stain positive for neurofilaments, which are part of the neuronal cytoskeleton.
Glial fibrillary acidic protein (GFAP) is an immunohistochemical marker that would be able to identify what two brain tumors?
Astrocytoma and glioblastoma
Glial fibrillary acidic protein (GFAP) is an immunohistochemical marker that identifies cells of glial cell origin, which are non-neuronal cells of the central nervous system. Tumors of glial cell origin that stain positive for GFAP include astrocytoma and glioblastoma.
In an 8 year old boy you have a CT scan of the head showing a supracellular cystic mass compressing the infundibular stalk. What tumor is it most likely?
craniopharyngioma. Any suprasellar lesion, including craniopharyngiomas, can compress the pituitary (infundibular) stalk, which can impede communication between the hypothalamus and the pituitary gland. This would likely lead to an increase in prolactin in this patient. Compression of this connection decreases the amount of dopamine delivery from the hypothalamus to the anterior pituitary gland. Dopamine normally inhibits the secretion of prolactin by the lactotroph cells. The loss of inhibition on lactotroph cells results in increased secretion of prolactin hormone (disconnection hyperprolactinemia). Increased prolactin levels would also decrease the levels of gonadotrophins (e.g., LH, FSH) by inhibiting GnRH release.
Hypercellular areas of spindle cells and hypocellular areas of myxoid stroma are characteristic findings of ______________________________, a tumor arising from cells of neural crest origin, which explains why they stain positive for S100.
vestibular schwannoma, Schwann cells are of neural crest origin, which explains why vestibular schwannomas stain positive for S100.
Whorls of densely packed cells with areas of lamellated calcification (psammoma bodies) suggest a ____________________.
meningioma
