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
Small blue cells arranged in rosettes around a central neuropil, known as Homer-Wright rosettes, suggest __________________________.
medulloblastoma
When he was a kid, Homer Wright took meds to mentally blast off
Closely packed capillaries and stromal cells filled with lipid vacuoles suggest ______________________, a tumor of blood vessels that is often associated with von Hippel-Lindau disease.
hemangioblastoma
Pleomorphic cells clustered around necrotic areas to form pseudopalisades suggest ____________________________, a malignant tumor of astrocytes.
glioblastoma multiforme (GM)
Cells with clear cytoplasm and a central round nucleus resembling a fried egg suggest ____________________________
oligodendroglioma or pinealoma
Calcifications and cholesterol crystals are typical histopathologic features of ______________________.
craniopharyngiomas
What tumors may you find in the region marked A?
Glioblastomas, which are highly malignant brain tumors located in the white matter of the cerebral hemispheres. Rare tumor of childhood.
What is the most likely tumor located at B?
oligodendroglioma, The frontal lobe is the most common location of oligodendrogliomas
What tumor is likely to be located at the region C?
Craniopharyngiomas which are relatively benign tumors that are located above the sella turcica but may also expand into the sella. They arise from the remnants of Rathke pouch near the pituitary stalk. Craniopharyngiomas are the most common cause of hypopituitarism in children and have a bimodal age distribution with peaks at 5–14 years and 50–75 years of age.
What tumor is likely to be at point D?
Pinealomas which are expected to arise from this region, which represents the pineal gland. The most common pinealoma in children is a germinoma, which would show undifferentiated germ cells on histology. Calcifications and cystic areas filled with cholesterol crystals, as seen in this patient, would not be expected.
What is likely to be located at point E?
The cerebellum is a frequent location of pilocytic astrocytomas, the most common benign brain tumor in children. Histopathology would show microcysts, Rosenthal fibers, and GFAP positive staining, none of which are seen in this patient.
What is likely to be located at F?
Medulloblastoma! The anterior cerebellum is a common location of medulloblastomas, the most prevalent malignant brain tumor in childhood. Histopathologic examination typically shows rosette-shaped small tumor cells (Homer-Wright rosettes). However, calcifications and cystic areas filled with cholesterol crystals as seen in this patient would not be expected. Medulloblastomas often extend into the 4th ventricle.
What is likely to be located at G?
Ependymomas which typically arise from the floor of the 4th ventricle. Although calcifications and cystic areas may be present in biopsy, histopathologic examination would also show characteristic ependymal rosettes with perivascular pseudorosettes. Moreover, cholesterol crystals would not be expected in ependymomas.
The eosinophilic, corkscrew-like processes seen on biopsy are called ______________
Rosenthal fibers
A collection of astrocytic processes that appear as eosinophilic, corkscrew-like fibers on histopathologic examination of pilocytic astrocytomas.
Rosenthal fibers are findings of what kind of tumor?
Pilocytic astrocytoma
____________________- is the most common pediatric primary brain tumor. It typically occurs in the cerebellum (posterior cranial fossa), but can also occur in supratentorial regions such as the optic nerve (optic glioma) and the cerebral hemispheres. Tumors in the posterior cranial fossa can present with dizziness, nausea, and clumsiness due to obstructive hydrocephalus and/or cerebellar damage.
Pilocytic astrocytoma
________________________ are the most common supratentorial tumors in pediatric patients; they are typically in the suprasellar region and cause bitemporal hemianopsia or endocrine abnormalities (e.g., hyperprolactinemia, hypopituitarism).
Craniopharyngiomas
Pleomorphic cells arranged in pseudopalisades are a hallmark of __________________________
glioblastoma multiforme
Most common origins of brain mets
- Lung
- Breast
- Melanoma
- Renal
- Colon
