Terms in this set (183)
What are the most common primary intraorbital tumors?
Lymphangiomas, hemangiomas, meningiomas, neurofibromas in adults.
Dermoid cysts, capillary hemangiomas, rhabdomyosarcoma, optic n glioma in children.
What are the most common tumors to spread into the orbit secondarily?
Sphenoid/clinoidal meningioma, sinonasal carcinoma
How are orbital tumors classified?
1) Intraconal (within the extraocular muscle cone, early visual loss and EOM impairment)
2) extraconal (present w/ proptosis)
3) intracanalicular (within the optic canal, present w/early visual loss, papilledema)
What is the guiding principle in choosing surgical corridor for orbital tumors?
Avoid crossing the plane of the optic nerve. Lateral orbitotomy for pathology lateral to the optic n; medial orbitotomy for medial pathology
What structures are present at the orbital apex?
Optic n. sheath meningioma
Lymphocytic infiltration/proptosis; resolves w/steroids
What are the most common non-neoplastic skull lesions?
Fibrous dysplasia, Langerhans cell histiocytosis, aneurysmal bone cysts, mucoceles, sarcoid granulomas, cholesterol granulomas
How does fibrous dysplasia usually present?
As a cosmetic deformity; painless, nonmobile mass in a young adult, most commonly affecting frontal, sphenoid, ethnoid, orbit.
What is the treatment for fibrous dysplasia?
Observation, bisphosphonate treatment, or agressive surgical resection.
What syndromes involve eosinophilic granulomas?
Dendritic cell disease, generally benign. multiple in Hand-Schuller-Christian dz (EG, DI, exophthalmos), Letterer-Siwe disease (most severe, young children)
What are aneurysmal bone cysts?
Benign, osteolytic, multicystic expansile lesions of bone. Tender, palpable scalp mass. Rx: complete resection.
What are the most common benign skull tumors?
Osteomas, hemangiomas, osseous meningiomas, giant cell tumors, epidermoid, dermoid
What benign skull tumor carries the highest recurrence risk?
Giant cell tumor. En bloc removal advocated; radiation avoided 2/2 risk of sarcomatous transformation
What are common malignant skull masses?
metastases, sarcomas, myeloma/plasmacytoma, chordoma
What population is affected by Langerhans cell histiocytosis/eosinophilic granuloma?
Median age 12 yo. Most commonly a solitary lytic lesion. Unknown cause, neoplastic vs. immunoregulatory disordder.
What syndrome is associated with multiple osteomas?
Gardner's syndrome-dominantly inherited w/colonic polyposis, soft tissue tumors, osteomatosis.
What is the first-line treatment for Paget's Disease?
Bisphosphonates or calcitonin. In comparison to fibrous dysplasia, Paget's usually symmetric, thickens inner cortex, older population. May progress to osteosarcoma.
What syndrome is associated with fibrous dysplasia?
McCune Albright syndrome, characterized by polyostotic fibrous dysplasia, endocrine hyperfunction (precocious puberty in females), cafe au lait spots. More common in females.
What are sinus pericranii?
Midline, abnormal collection of veins on outer table draining intracranially through diploic/emissary veins often into ant sagittal sinus. Overlying skin hairless, tinged blue. Slow progression is the norm.
What is the site of origin of juvenile nasal angiofibromas?
Sphenopalatine foramen. The lesion contiguously extends anteriorly into the nasal cavity, posteriorly into the nasopharynx, and laterally through the pterygomaxillary fissure into the infratemporal fossa.
Which gender is more affected by JNA?
Males, usually ages 14-25, who present with epistaxis, nasal obstruction, proptosis, diplopia.
What are possible surgical approaches JNA?
Transnasal, transpalatal, lateral rhinotomy, facial degloving, Lefort I, infratemporal fossa. Preop embolization is recommended.
What is the prognosis of JNA?
Generally benign following resection; residual tumor often stable or may regress at puberty.
What are the most common sites of intracranial schwannomas?
1) Vestibular, 2) trigeminal, 3) facial 4) jugular foramen
What is Meckel's cave?
Upon entering porus trigeminus, it is the space occupied by the trigeminal nerve between two leaflets of dura, inferior to sup. petrosal sinus and posterolateral to sella, cavernous sinus.
What are the trigeminal-innervated muscles?
Muscles of mastication (temporalis, masseter, med and lat. pterygoid), tensor veli palatini and tensor tympani, ant. digastric, mylohyoid muscles
How are trigeminal schwannomas classified?
Based on location; A) middle fossa, (35%) B) posterior fossa,(20%) C) dumbell (35%) D) extracranial (10%)
This dictates approach...pterional/subtemporal/Dolenc(A); retrosigmoid(B); transpetrosal/transtentorial (C); infratemporal (D)
How do trigeminal schwannomas present?
Trigeminal hypoesthesia/lancinating pain, abducens palsy, HA.
What radiosurgical dose is used for trigeminal schwannomas?
13-18 Gy, similar to vestibular schwannomas. SRS recommended for small, residual, or recurrent tumors.
What are the risk factors for sinonasal neoplasms?
Smoking, industrial operations, woodworking
What is the most common histology of sinonasal neoplasm?
Squamous cell. Also olfactory neuroblastoma, adenocarcinoma, adenoid cystic carcinoma, sinonasal undifferentiated carcinoma, osteosarcoma.
What are the most common sites of sinonasal neoplasm?
Maxillary antrum, ethmoid sinuses. Also may spread perineurally via V2, V3.
What is the standard treatment for sinonasal ca?
Rx: complete tumor resection w/margin and adjuvant fractionated XRT (60Gy). Transcranial and/or transfacial approach.
How do esthesioneuroblastomas present?
(AKA olfactory neuroblastoma) Nasal obstruction, recurrent epistaxis. Two peaks in incidence in 2nd + 5th decades.
What is the standard treatment for esthesioneuroblastoma?
XRT preop or postop, +/- chemo. Resection via frontoethmoidal approach...15yr disease free survival 60-80% reported. Recurrence common.
Where do esthesioneuroblastomas originate?
From olfactory epithelium. Similar features to neuroblastomas of adrenal glands and sympathetic nervous system.
How are sinonasal cancers staged?
Stage A-confined to nasal cavity
Stage B-tumor extension to paranasal sinuses
Stage C-involvement of cribriform plate, skull base, intracranial cavity, or orbit
Stage D-metastases to cervical nodes or distant sites
Where do esthesioneuroblastomas metastasize?
Cervical nodes. May metastasize up to 1/4 of cases.
Describe a facial degloving approach.
Describe a lateral rhinotomy approach.
What is the cell of origin of the glomus tumor?
Paraganglion tissue, from neural crest, origin of the parasympathetic nervous system. "Neurocrine" cells, including adrenal medulla, carotid body.
What are the common sites for glomus tumors?
1) Adventitia of dome of jugular bulb ("glomus jugulare")
2) Jacobson's n. (tympanic br of glossopharyngeal n.; in middle ear); ("glomus tympanicum")
3) Arnold's n. or auricular branch of vagus, infratemporal fossa ("glomus vagale")
What adjuvants are recommended for glomus tumor treatment?
Preoperative embolization. SRS is being increasingly used.
What is the typical presentation of glomus tumors?
Pulsatile tinnitus, hearing loss, hoarseness, swallowing difficulty, dizziness or facial plasy. Generally indolent, locally invasive/destructive. 1/1,000,000 people.
What is the most common approach to a glomus jugulare tumor?
"Lateral skull base approach"
Sectioning of EAC, complete mastoidectomy w/skeletonization of the sigmoid sinus, jugular bulb, and transposition of facial nerve. Upper neck dissection w/exposure of CN IX-XII along IJV. Ligation of sigmoid sinus and JV proximal and distal to tumor. "Intrabulbar" tumor removal. May be combined with retrosigmoid craniotomy.
What approach is recommended for glomus tumors extending rostral to carotid canal?
An infratemporal fossa appraoch, extended rostrally to ear canal (sutured closed) to expose and isolate caroitd all the way to cavernous sinus and up to f. ovale or rotundum. Best exposure for large GTs growing rostrally.
What are possible compications of glomus tumor resection?
Lower cranial nerve palsy, requiring possibly medialization of paralyzed vocal cords, gastrostomy, tarsorraphy for facial palsy, hearing loss, CSF leak.
Where do chordomas most commonly arise?
1/3 clivus, 1/3 sacrum, 1/3 spine. Chordomas tend to be midline, whereas chondrosarcomas are usually paramedian.
What is the origin of chordomas?
Notochordal rests (midline).
How are chordomas managed?
Surgical excision primary. Approaches include transsphenoidal, transbasal, transpetrosal, far lateral. SRS and proton beam are also offered due to high local recurrence rate.
What are the most common lateral ventricle tumors in adults?
Meningioma, central neurocytoma, ependymoma, subependymoma.
What are the most common tumors of the third ventricle?
colloid cyst, craniopharyngioma, hypothalamic glioma, meningioma, hypothalamic hamartoma, pineal tumors, tectal glioma
What are the most common lateral ventricle tumors in children?
subependymal giant cell astrocytoma, choroid plexus tumors, ependymoma, and astrocytoma
How do subependymomas present?
Often asymptomatic/incidental, older adults.
What is the pathologic hallmark of central neurocytomas?
Solid sheets of uniform, round, synaptophysin positive cells, perivascular pseudorosettes, honeycomb.
Where do intraventricular meningiomas typically arise?
Most commonly arise at L atrium in adults.
Where do colloid cysts arise?
Roof of third v; full of gelatinous viscous material. Present w/headache/obstructive symptoms, or asymptomatic.
Where do central neurocytomas occur?
Lateral> third ventricle, at f. of Monro, often adherent to septum.
What is the epidemiology of choroid plexus papillomas?
0.5% of adult, 2-5% of pediatric brain tumors. most common tumor in <2yo.
What is the appearance of choroid plexus papilloma?
well circumscribed, cauliflower-like lesions. Often have calcification, hemorrhages, cysts.
What syndrome are hypothalamic gliomas associated with?
How does a hypothalamic hamartoma typically present?
gelastic seizures, precocious puberty
What is the most common lesion of the pineal gland?
What are the categories of pineal tumors?
60% are germ cell tumors (Of these, 2/3 germinomas and 1/3 non-germinomatous(teratoma, chorioca, yolk sac, embryonal, mixed),
15% pineal parenchymal cell tumors
Others-glial cell tumors, and miscellaneous.
Cannot be differentiated by imaging alone.
How do pineal masses present?
Most commonly 2/2 obstructive hydrocephalus, oculomotor/gaze signs, rarely endocrine dysfunction.
How are deep venous structures displaced by pineal tumors?
Pineal tumors generally displace the veins superiorly, along dorsal surgace of tumor. Exceptions include ependymomas of corpus callosum or meningiomas.
What is the significance of tumor markers?
Serum alpha-fetoprotein or beta-hCG is pathognomic for malignant germ cell elements. However, the converse is not necessarily true; these tumors may be present without elevated markers. These markers make surgery unnecessary, proceed directly to radiation and chemo.
What is the management of pineal region masses?
Management of symptomatic hydrocephalus, tissue diagnosis. Germinoma best treated w/XRT. Nongerminomatous germ cell tumors treated with radiation, chemo, and surgery for any residual mass. Pineocytomas treated by radical surgery. Pineoblastomas Rx: radical surgery, chemo, XRT. Long term control possible.
What is the embryologic origin of dermoids and epidermoids?
Problem at gastrulation, w/dermoid and epidermoids coming from surface ectoderm and neurenteric cysts arising from endoderm
Where do epidermoid cysts commonly occur?
CPA or parasellar cisterns. Insinuate around nerves and vasculature. Pearly flakes of keratin. CA 19-9 positive.
In what age group do dermoid cysts occur?
Younger, avg age 15. Benign, cause mass effect, contain dermis, hair follicles, sebaceous glands. Midline.
Rare malformations, spinal or cranial, pontomedullary, CPA, parasellar, craniocervical junction. Strong association w/spinal malformations, cleft vertebrae, hemivertebrae, spinna bifida,
What is the origin of craniopharyngiomas?
Believed to be from Rathke's pouch. Stomodeum invaginates and migrates superiorly (Rathke's pouch, becomes adenohypophysis), meets neuroepithelium migrating inferiorly from hypothalamus (becomes neurohypophysis).
What is the epidemiology of craniopharyngioma?
1 per 1,000,000 per year. Adamantinomatous subtype has two age peaks (5-15 and 45-60). Papillary exclusively 40-55 yo.
How do craniopharyngiomas present?
3 clinical syndromes: visual dysfunction (most common in adults, hemianopia or monocular loss), hypothalamic-pituitary disturbance (hypogonadism in adults, GH def in children), raised ICP/CSF obstruction(pediatric).
What are the pathologic subtypes of craniopharyngioma?
Papillary (30% of adult cases)--well circumscribed, solid, bland mass of squamous cells forming pseudopapillae
Adamantinomatous--lobulated cystic and solid mass, crankcase oil fluid, calcification, fibrosis, cholesterol rich deposits. Squamous epithelium in cords, lobules, surrounded by palisaded columnar epithelium, "wet keratin"
How are craniopharyngiomas treated?
Initially, treat hydrocephalus, assess endocrine status. Controversy over total resection vs. subtotal decompression + SRT. Subfrontal, transsphenoidal, pterional/orbitofrontal, transcallosal approaches. Endocrine dysfunction (panhypopit and DI) common postop, also hypothalamic injury and optic decline.
What are the three most common primary brain tumors?
1) Glioma 2) Meningioma 3) Pit adenoma.
How is the anterior pituitary organized?
Bilobed, ant adenohypophysis (80% by volume, GH, PRL, ACTH, TSH, LH/FSH) GH cells along lateral wings, along ant face. Lactotrophs anywhere. Corticotrophs in central wedge.
How do pituitary adenomas present?
1) Pituitary hyperfunction 2) adenohypophysis insufficiency 2/2 mass effect (in order, gonadotrophs, thyrotrophs, somatotrophs, corticotrophs lose function; almost never see DI with an adenoma) 3) Mass effect--HA, vision loss, hypothalamic/vegetative symptoms.
What is the stalk effect?
Moderate hyperprolactinemia (<150ng/mL) due to destruction/compression of stalk/hypothalamus, releasing lacrotrophs from dopamine inhibition.
How does pituitary apoplexy present?
Precipitous loss of vision, altered LOC, ophthalmoplegia, acute adrenal insufficiency. Urgent glucocorticoid replacement and surgical decompression warranted. Many tumors show radiographic evidence of hemorrhage
What are the surgical indications for pituitary adenomas?
Pituitary apoplexy, progressive mass effect w/visual loss (check PRL first), hyperfunctioning tumor w/Cushing's acromegaly, secondary hyperthyroidism, intolerance of medical therapy for prolactinomas
What are potential complications of transsphenoidal surgery?
CSF leak, meningitis, hypothalamic injury, visual damage, arterial injury, cavernous sinus injury, iatrogenic hypopituitarism
When is a transcranial approach required?
Needed for <5% of cases, for large suprasellar or third ventricular extensions. Pterional approach, usu. between optic nerves or between optic and carotid.
What is the most common sybtype of pit adenoma?
Prolactinoma and nonsecreting tumors are 30% each. Followed by GH and ACTH tumors.
How do prolactinomas typically present?
Hypogonadism, menstrual dysfunction, galactorrhea.
What is normal prolactin level and what level is indicative of prolactinoma?
Normal <20ng/mL. >200 definite prolactinoma. In between uncertain.
Why does prolactin level matter?
Predictive of surgical cure rate...cure difficult w/prolactin>200. Recurrence often manifests endocrinologically.
How are prolactinomas managed?
Bromocriptine (D2 agonist) is primary. Surgery indicated for apoplexy, cystic prolactinomas, failure/resistance to dopaminergic therapy. Recurrence rate w/surgery 20%; manifests as increased PRL; fertility restored in 80%.
How do GH adenomas present?
Most are macroadenomas w/mass effect, cause acromegaly. Elevated GH basal level >5ng/mL, insufficient suppression on OGTT (>2ng/mL), elevated IGF-1 levels. GHRH secreting tumor is rare cause of pit enlargement and GH excess. 1/3 have modest PRL elevations.
How are GH adenomas managed?
Surgery usu. initial treatment, may be curative depending GH levels, invasiveness. Medical therapy and SRS are adjuvant/salvage. Cure variably defined but approx 50%. Recurrence 6-8% after cure.
What constitutes biochemical remission in GH adenoma?
Definted as OGTT suppression of GH to less than 1ng/mL and normalization of IGF-1 levels, or as mean GH less than 2.5.
What medical therapies are used in GH adenomas?
Somatostatin analogues (octreotide) and pegvisomant (GH receptor antagonist, decreases IGF-1 levels).
What is the differential diagnosis of Cushing syndrome?
ACTH dependent-80%--Pituitary adenoma ("Cushing disease"-85%), ectopic ACTH lesions (15%--lung, carcinoud, medullary thyroid, islet cell)
ACTH independent-20%--adrenal tumor/hyperplasia ,exogenous steroids.
How do ACTH adenomas present?
Weight gain, centripetal fat distribution, moon facies, buffalo hump, skin thickening, easy bruising, striae, hirsutism, hypertension, glucose intolerance, osteoporosis, infertility.
How are ACTH adenomas diagnosed?
Step 1) Establish hypercortisolemia via urine 24hr free cortisol, and low-dose dexamethasone suppression test
Step 2) Differentiating ACTH-dependent vs. ACTH-independent cause: Measure ACTH level
Step 3) Differentiating Cushing's Disease from Ectopic ACTH sources--High-dose dexamethasone test-corticotroph adenomas generally suppress. CRH stim test--corticotroph adenomas have a strong positive response to CRH. Inferior petrosal sampling to confirm and determine side of adenoma.
How are ACTH adenomas treated?
Surgically. Finding the usually small microadenoma in the normal gland is the challenge, esp when not visualized on MRI.
When is ACTH adenoma cure apparent?
By 2nd or 3rd postop day, w/morning cortisol levels < 5ug/dL and undetectable serum ACTH.
What are options for recurrent or residual disease?
Repeat transsphenoidal exploration, SRS, medical therapy, and as a last resort, bilateral adrenalectomy.
What is Nelson's syndrome?
Rapid enlargement of ACTH adenoma, usually after bilateral adrenalectomy. Tremendous secretory activity, elevated ACTH, MSH. Often requires repeat resection and radiotherapy.
What are the most common CPA masses?
VSs are 80% of all CPA masses, followed by meningiomas and epidermoids.
What is the gross and histopathology of vestibular schwannonomas?
Usu. arises from inf vestibular nerve, less often sup vestibular nerve. Rubbery/nodular, rarely cystic. Classically originates from IAC, grows into CPA. Microscopically Antoni A (fascicles of spindle-shaped cells) and Antoni B (more myxoid stroma). NF2 syndrome w/NF2 gene, merlin tumor suppressor protein.
How do vestibular schwannomas present?
Early sensorineural hearing loss, often w persistent tinnitus. Possibly vestibular sxs (imbalance, dizziness), rarely brainstem symptoms/hydrocephalus.
How are vestibular schwannomas managed?
Observation for small/medium size tumors in elderly. Radiosurgery for growing tumors <2.5cm, 13 Gy dose minimizes facial/trigeminal neuropathy (<5% each). Surgery for large tumors with brainstem compression.
What surgical approaches are used for vestibular schwannomas?
Retrosigmoid--classic, large or small tumors, allows hearing preservation. May drill out IAC intradurally. Middle fossa--introduced by House for small intracanalicular tumors to preserve hearing. Translabyrinthine--mastoidectomy, entire IAC exposed, hearing not preserved, early ID of facial nerve.
What are the most common surgical complicatinos for vestibular schwannomas?
Facial weakness, hearing loss, CSF leak, AICA injury, hydrocephalus
What is the House Brackmann scale?
Grade I-normal in all areas Grade II-mild dysfunction Grade III-obvious weakness, complete eye closure Grade IV-incompete eye closure, obvious weakness, disfiguring asymmetry, Grade V-barely perceptible motion Grade VI-complete paralysis
What is the Gardner-Robertson scale?
Hearing--grade I+II useful (Pure tone average <50dB, Speech discrimination score >50%). Grade III+IV nonserviceable.
Where is the facial nerve in relation to a vestibular schwannoma?
Usually anterior to tumor. Facial nerve is anterior/superior quadrant at IAC/Bill's bar.
Where do ependymomas arise?
2-6% of intracranial tumors in adults, Foramen of Luschka (kids) and lat ventricle trigone (adults). Uniform cuboidal and fibrillary cells arranged into linear tubules "rosettes" and perivascular pseudorosettes. Chr 22 aberrations common.
What is the treatment and prognosis of ependymoma?
Total resection ideal; postop local XRT or SRS is controversial w/GTR.
5-10 yr PFS 75-80% w/GTR.
What is the epidemiology of PNET?
Children>adults; 20% of childhood brain tumors; seen in Gorlin's syndrome, Li-Fraumeni syndrome, and Turcot's syndrome. PNET includes pineoblastoma, retinoblastoma, medulloblastoma.
What are the pathologic hallmarks of PNETs?
May show neuronal and/or glial differentiation. 40% show Homer-Wright pseudorosettes(nuclei around a central clear area rather than a vessel). Astrocytic differentiation w/GFAP in 50%. Grossly soft, friable purplish tumors. Continuous sheets of small round, blue-cell tumors, hyperchromatic nuclei and minimal cytoplasm.
How do PNETs present?
Increased ICP, morning HA, n/v. Unsteady gait, ataxia, head tilt 2/2 6th n. palsy or dural traction.
What is important to check for in PNET w/r/t imaging?
Check entire neuraxis for dissemination.
What is standard treatment for PNET?
Total resection gives best prognosis, chemo (CCNU, vincristine, MTX) and XRT (craniospinal irradiation and post fossa boost). Cognitive and endocrine sequelae w/XRT. XRT avoided <3yo
What is the outcome of PNET?
Overall 66% 5-yr survival. Depends on age, extent of resection, and metastasis. Up to 90% 5 yr survival w/complete resection, but recurrence usually incurable.
What is the origin and genetics of medulloblastoma?
Inf medullary velum/vermis stem cells from external granular later "granule neuron precursors". 17p loss common. Recently being classified by molecular changes: Wnt (good prognosis). GFAP + associated w better px.
What are the characteristics of subependymal giant cell astrocytoma?
Seen in tuberous sclerosis. Rarely symptomatic, due to obstruction of Monro. Well demarcated, indolent. Giant cells w/abundant eosinophilic cytoplasm. May have mitoses, necrosis or endothelial proliferation, but not agressive. Intraventricular, symptoms usually due to obstruction of Monro.
What clinical findings are seen in tuberous sclerosis?
Autosomal dominant, MR, seizures, adenoma sebaceum. Also altered pigmentation, retinal tumors, subungual fibromas, spleen, pancreas tumors.
What newly recognized tumor of the pineal region is diffusely enhancing and well demarcated from brain?
Papillary tumor of pineal region. Eosinophilic cells, perivascular pseudorosettes. Slow growing, surgery optimal.
What tumors are common in the temporal lobe in young patients with epilepsy?
Dysembryoplastic neuroepithelial tumor (neuronal and glial),
Ganglioglioma(has neuronal and glial markers),
Pleomorphic xanthoastrocytomas (cystic w/mural nodule; bizarre astrocytes).
What recently recognized presents as an ovoid, diffusely enhancing mass of the suprasellar area?
Chordoid Glioma of Third ventricle. Grade II, recognized in 1998. Anterior third ventricle, cause HCP, diffusely enhance, noninflitrative, GFAP and vimentin mositive, mucinous stroma. May progress.
How do malignant gliomas present?
1/2 of adult intracranial tumors. AA avg age 40, GBM avg age 53. Gliosarcoma 2-8% of GBM. Present w/raised ICP sxs-HA, n/v, blurry vision, drowsiness. Focal deficits or cognitive/personality change.
What are the pathologic differences between grade III and IV gliomas?
Grade III display mitotic activity and nuclear atypia. Grade IV show endothelial proliferation and necrosis. GBM variants include gliosarcoma, giant cell, small cell (assoc w EGFR amplification). Increased MIB-1/Ki-67 index proportional to grade.
What molecular changes are seen in Primary GBM?
EGFR amplification in 50%, may become constitutively active.
PTEN tumor suppressor in another 50%, negatively regulates the PI3K pathway, rare in lower grade gliomas.
What molecular changes are seen in secondary GBM?
TP53 mutations common, involved in cell cycle/death/differentiation. First detectable mutations in 2/3 of precursor low grade astrocytomas.
What is histological markers are seen in gliosarcomas?
GFAP and vimentin positive in glial and sarcomatous portions, respectively.
What is the significance of MGMT epigenetic silencing in GBM/AA?
MGMT promoter methylation (epigenetic silencing) status predicts chemo response (positive methylation predicts improved response to temodar and longer survival).
What dose and regimen of XRT is used for GBM/AA?
60Gy in 30 fractions to tumor and involved field
What are the histologic types of low grade gliomas?
Include astrocytic, oligodendroglial, ependymal, or mixed histologies. 15% of adult brain tumors. P/w seizures in 50-80%.
What genetic alterations are seen in low grade gliomas?
loss of p53 most commonly, on Chr 17p. >1/2 of oligodendrogliomas show loss of 1p and 19q.
What is the role radiation therapy in low grade gliomas?
RCTs show no dose-response relationship for higher doses (2 RCTs, 50 vs 60Gy), and no benefit to initial radiotherapy over delaying until disease progression (EORTC 22845).
What is the role of chemotherapy for low grade glioma (excluding oligodendroglioma)?
A Southwest Oncology Group study randomized 54 adults with incompletely resected LGG to RT alone or RT plus CCNU (lomustine) chemotherapy. There was no difference in outcome between the 2 treatment arms. Temozolomide and PCV (procarbazine, CCNU, and vincristine) used for salvage.
From what cells do meningiomas originate?
Arachnoid cap cells in arachnoid villi
What are the most common locations of meningiomas?
Convexity 35%, Parasagittal 20%, Sphenoid ridge 20%, Intraventricular 5%, Tuberculum sellae 3%, Intratentorial 13%
What histologic subtypes qualify as WHO Grade II+III meningiomas?
Grade II- atypical, clear cell, chordoid, Grade III-rhabdoid, anaplastic, papillary
What immunohistochemical markers are positive in meningioma?
80% EMA (epithelial membrane antigen) positive; Vimentin positive, E-cadherin positive
What is the most common genetic alteration in meningiomas?
Loss of 22q. Several suspect genes are on Chr 22q, including NF2 gene, which makes merlin.
What is the significance of hormone receptors in meningiomas?
Progesterone receptor expression signals good prognosis. Lack of PR or presence of estrogen receptor is negative.
What is the significance of a high T2 signal intensity in a meningioma?
High T2 intensity suggests high water content, easy suckability.
What molecular markers suggest higher meningioma recurrence rates?
Recurrence predicted by MIB-1 and VEGF expression.
What are dosage and indications for meningioma SRS?
Mean dose to tumor margin 14 Gy (UPMC). Indications: postop for malignant meningioma, incomplete resection with repeat surgery that would be high risk, multiple recurrent tumors, inoperable patients w/symptomatic tumors
What is the blood supply of the typical trigone intraventricular meningioma
Blood supply from ant choroidal, may be approached via middle temporal gyrus or parietal lobe.
Tuberculum Sellae Meningiomas
5-10%. W>>M. Chiasmal syndrome w/primary optic atrophy and bitemporal field deficits. Anosmia late finding.
Optic N and Orbit Meningiomas
Progressive visual loss and proptosis
How do petrous meningiomas present?
Hearing loss, facial pain, numbness, weakness/spasm. Trochlear n usually sup and lateral, trigeminal sup and ant. abducens anterior, VII and VIII anterior, IX, X, XI inferior.
What characterizes the clinical course of hemangiopericytoma?
Malignant, may metastasize similar to sarcoma. 2-4% of meningeal tumors. Extremely vascular. Mitoses, strong reticulin staining, genetically distinct from meningiomas. Shorter duration of symptoms, recurrence rate high. Radiosurgery indicated.
What are the arterial supplies of the common locations of meningiomas?
What are the most common sources of brain mets?
Afflicts one quarter of adult cancer pts. Most common sources are lung, breast, and melanoma. Melanoma, lung, and breast have the highest propensity to metastasize to the brain.
What is the radiation regimen for brain metastases?
Standard dose is 30Gy in 10 fxns. Immediate complications are fatigue, which may last weeks, hair loss, scalp erythema and pigmentation. Long term dementia risk is often overshadowed by threat of recurrent disease.
For what type of cancer is prophylactic cranial irradiation indicated?
Given high risk of brain mets in SCLC (30%), PCI has been shown to improve survival and lower risk of brain mets.
High-risk childhood ALL has also historically received PCI, but now may be omitted with more recent chemo.
Is there evidence to support resection of brain metastases?
Yes, was shown superior to WBRT alone for single mets with controlled systemic disease and good KPS by Patchell et al.
What histologies have traditionally been considered radiosensitive and radioresistant?
Radiosensitive include SCLC, lymphoma, germ cell. Radioresistant include melanoma and RCC.
This may not apply to SRS.
Melanoma pts have poorer survival in general.
What is the role of postoperative WBRT after resection or radiosurgery of all visible metastases?
Unclear role--one RCT showed improve local control but no survival advantage. Esp questionable in radioresistant tumors, melanoma and RCC.
What is the role of SRS in brain metastases?
20 Gy standard dose. Improves survival compared to WBRT alone. Appropriate for mets less than 3cm, probably equivalent to surgery. WBRT may be unecessary after SRS of a few mets.
What is the role of chemotherapy for brain metastases?
Experimental apart from germ cell and small cell lung ca.
What diagnosis should be considered in cancer patients with diplopia, headache, cranial neuropathies, or back pain?
Neoplastic meningitis. Most commonly seen w/breast, lung, GI, melanoma, high risk lymphomas. Survival 3-6 mos. 4-8% of patients w solid tumors. CSF cytology, elevated protein. +/- IT chemo via Ommaya.
What type of cells make up primary CNS lymphoma?
90% diffuse large B cell type, show angiocentric clustering
Where are primary CNS lymphomas found?
Usually homogeneously enhancing; half are solitary, subcortical, thalamus, BG, or periventricular
What is the prognosis of CNS lymphoma?
Depends on age, performance status, deep tumor location. 2 yr survival varies from 80 to 15% depending on these factors.
What is standard management of CNS lymphoma?
MTX and WBRT is routine "combined modality" therapy. Hold steroids prior to biopsy...they provide brief but dramatic response. Intrathecal MTX is controversial. Neurotoxicity common (25%) with WBRT--subcortical dementia.
What is the management of HIV enhancing brain lesions?
Initial treatment of enhancing brain mass is anti-toxo for 2 wks as this is most common diagnosis. Biopsy if no response. HAART is best therapy if not already started.
What is secondary CNS lymphoma?
Usu. NHL, often testicular or Burkitt's; more often leptomeningeal.
What are the most common locations for hemangioblastomas?
90% cerebellum (posteromedial), brainstem (obex), or spinal cord (posterior column)
What is the most common adult posterior fossa primary brain tumor?
Hemangioblastoma. Enhancing nodule with peritumoral cyst.
What other tumors are seen in von Hippel Lindau disease?
Hemangioblastomas, endolymphatic sac tumors, also renal cysts, renal cell ca, pancreas cysts/tumors, pheochromocytomas. Dominantly inherited due to mutated VHL tumor suppressor gene.
What is the origin of hemangioblastomas?
Derived from hemangioblasts, which are embryonic cells capable of blood and vessel formation.
Does the hemangioblastoma cyst wall need to be resected?
No. It is non-neoplastic. The nodule must be removed. Surgical resection is curative.
Describe the histology of hemangioblastomas.
2 distinct cellular components that may occur in the same tumor in different proportions. The first type is small, perivascular, endothelial cells that have dark compact nuclei and sparse cytoplasm. Cells of the second type contain multiple vacuoles and granular eosinophilic cytoplasm rich in lipids, similar to renal cell ca.
What are the three most common surgical approaches to vestibular schwannomas?
Retrosigmoid, translabyrinthine, and middle fossa.
What structures may be lie unprotected on the floor of the middle fossa?
The geniculate ganglion lies exposed on the middle fossa floor in 15% of cases; the greater superficial petrosal nerve is usually uncovered for part of its course, and the carotid in the carotid canal may be exposed as well.
Describe the middle fossa approach to a vestibular schwannoma.
A temporal craniotomy is performed anterior to the ear. Temporal dura is elevated from the middle fossa floor, and bone is removed to expose the geniculate ganglion. From the geniculate ganglion, the labyrinthine segment of the facial nerve is exposed between the cochlea and the superior semicircular canal (without disturbing either).
What is the arcuate eminence?
A bony prominence on the middle fossa floor that overlies the superior semicircular canal.
What is characteristic of intra-axial tumors on MRS?
As a general rule, as malignancy increases, NAA and creatine decrease, and choline, lactate, and lipids increase. NAA decreases as tumor growth displaces or destroys neurons.� Very malig-nant tumors have high metabolic activity and deplete the energy stores, resulting in reduced creatine.� Very hypercellular tumors with rapid growth elevate the choline levels. Lipids are found in necrotic portions of tumors, and lactate appears when tumors outgrow their blood supply and start utilizing anaerobic glycolysis.
How can MRS distinguish between radiation necrosis and tumor recurrence?
Elevated choline is a marker for recurrent tumor. Radiation change generally exhibits low NAA, creatine, and choline on spectroscopy. If radiation necrosis is present, the spectrum may reveal elevated lipids and lactate.
High amino acids on MRS in an intraxial mass suggests what diagnosis?
Cerebral abscess. (Succinate, acetate, alanine, and glycine)
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