Tumor Flashcards
Which of the following is the most common ring-enhancing lesion in a patient who has HIV
infection?
Answers:
A. CNS Lymphoma
B. Progressive Multifocal Leukoencephalopathy
C. Toxoplasmosis
D. Cryptococcus abscess
E. Pyogenic Abscess
Toxoplasmosis
Approximately 50% of patients who develop acquired immunodeficiency syndrome (AIDS) will develop neurologic symptoms. The most common focal lesions that are encountered in these patients are: Toxoplasmosis (32% patients) Primary CNS Lymphoma (~5% patients) PML – Progressive multifocal leukoencephalopathy (2% patients) Cryptococcus (13% patients) Tuberculosis <1% Toxoplasmosis is the most common of these infectious agents that cause ring enhancing lesions in patients with AIDS. These lesions typically occur late in the disease course when CD4 counts are low (<200) PML – Caused by the JC virus which leads to focal demyelination. Typically affects the white matter and does not enhance. CNS Lymphoma – Unlike in immunocompetent individuals, lesions secondary to CNS lymphoma in HIV do not necessarily always have homogenous enhancement and can have central regions of necrosis on imaging. Nevertheless, the most common ring enhancing lesion in patients with HIV is Toxoplasmosis Cryptococcal abscesses can ring enhance, but are not as common as toxoplasmosis. Cryptococcus can also present with meningitis in patients with AIDS. Pyogenic abscesses will ring enhance, but these are not the most common ring enhancing lesions in patients with HIV/AIDS.
A 65-year-old man is evaluated because of bitemporal hemianopia. Endocrine testing is normal. A
CT scan is shown. Which of the following is the most likely diagnosis?
Answers:
A. Aneurysm
B. Chordoma
C. Craniopharyngioma
D. Histiocytosis X
E. Pituitary adenoma
Craniopharyngioma
Craniopharyngiomas comprise the most common type of non-glial intracranial tumor in children, representing between 5% and 10% of pediatric brain tumors. However, they exhibit a bimodal distribution, with a smaller peak occurring in adults over 40 years old. Common presentations include headache, hydrocephalus, raised intracranial pressure, visual loss (typically bitemporal hemianopsia), papilledema, and endocrine dysfunction (hypopituitarism and diabetes insipidus). Rarely, spontaneous cyst rupture results in aseptic chemical meningitis. Pathological subtypes of craniopharyngioma include adamantinomatous and squamous papillary; the former predominates in pediatric patients. On imaging tend, these tumors are often mixed cystic/solid suprasellar tumors, with calcifications (seen in the majority of adamantinomatous tumors). These are especially evident on CT scan. Appropriate surgical approaches include various craniotomies (interhemispheric, fronto-temporal, pterional, etc.) and transsphenoidal surgery for smaller, intrasellar lesions or for the intrasellar remnants of larger lesions. Total surgical excision, although difficult to achieve because of the sensitive location of these tumors, may be curative. For a residual or recurrent cystic component, intracavitary radiation or bleomycin chemotherapy may be helpful. For residual or recurrent solid component, stereotactic radiosurgery may be helpful. Chemotherapy is relatively ineffective for this tumor type. Some degree of pituitary dysfunction is extremely common after resective surgery and pan-hypopituitarism is frequently seen. Hydrocephalus is rare, particularly in lesions that do not involve the posterior third ventricle. Seizure disorder can result from damage to fronto-temporal cortex during the approach but is rare. While exacerbation of visual dysfunction is not uncommon, total blindness is relatively rare after tumor removal.
Which of the following findings is most specific for the diagnosis of Korsakoff psychosis?
Answers:
A. Mesial temporal lobe sclerosis
B. Hippocampus atrophy
C. Atrophy of mamillary bodies
D. Caudate atrophy
E. Bilateral globus pallidum lesion
Atrophy of mamillary bodies
Korsakoff syndrome is characterized by marked deficits in anterograde and retrograde memory, apathy, an intact sensorium, and relative preservation of long-term memory and other cognitive skills. Confabulation is a feature in some but not all cases. Attention and social behavior are relatively preserved. Memory impairment correlates better with lesions in the anterior thalamus rather than mamillary bodies. Nonetheless, atrophy of the mamillary bodies is a relatively specific sign of prior WE, and the finding of small mamillary bodies in a demented patient should raise the possibility that alcohol abuse and malnutrition have contributed to the dementia. Other areas of disproportionate focal volume loss on magnetic resonance imaging (MRI) that appear to be relatively specific for KS include the medial thalami and corpus callosum
Following surgical resection of glioblastoma, standard therapy includes radiotherapy with
concomitant and adjuvant temozolomide. What is the standard radiation dose given in 30
fractions?
Answers:
A. 20 Gy
B. 40 Gy
C. 30 Gy
D. 60 Gy
E. 50 Gy
60 Gy
The standard radiation dosing for glioblastoma is thirty 2 Gy doses delivered 5 days per week for 6 weeks for a total dose of 60 Gy. Other dosing regimens are used but this is considered standard due to this regimen being implemented in the Stupp protocol.
A healthy 28-year-old woman is being evaluated because of a two-month history of amenorrhea
and mild headaches. She is not taking any medications. Laboratory studies show normal thyroid
function and a serum prolactin level of 89 ng/mL (N < 30). Which of the following is the most
important next step in evaluation?
Answers:
A. Carbergoline therapy
B. Petrosal sinus sampling
C. 1:100 serum dilution and repeat prolactin assay
D. Glucose tolerance test
E. Dexamethasone suppression test
1:100 serum dilution and repeat prolactin assay
In women of childbearing age, hyperprolactinemia is one of the most common causes of anovulation. Prolactinomas are the most common pituitary tumor and the most frequent cause of persistent hyperprolactinemia. A serum prolactin level greater than 200ug/mL suggests a diagnosis of a prolactinoma rather than disinhibition of dopaminergic input to the prolactin secreting cells from mass effect of a non-prolactin secreting pituitary adenoma. However, very high levels of serum prolactin levels (ie.>10,000ug/mL) may saturate the prolactin assay leading to falsely low tests results. This is termed the “Hook Effect.” When a prolactinoma is suspected, serum prolactin testing should be re-run at 1:100 dilution. An MRI will can confirm the presence of a pituitary adenoma. Carbergoline therapy is a first line treatment for a prolactinoma once the diagnosis has been established. Petrosal sinus sampling and the dexamethasone suppression test are part of the work up of Cushing’s disease.
Which of the following EEG findings is most characteristic of herpes simplex virus type 1
encephalitis?
Answers:
A. Periodic Sharps Waves
B. EEG desynchronization
C. Isoelectric Electroencephalogram
D. Alpha Waves
E. Periodic Lateralizing Epileptiform Discharges
Periodic Lateralizing Epileptiform Discharges
Herpes simplex encephalitis is a multifocal necrotizing and hemorrhagic encephalomyelitis that usually affects the temporal lobes. Patients typically presented with confusion, fever and seizures. EEG typically is notable for Periodic Lateralizing Epileptiform Discharges. When present bilaterally, HSE is extremely high on the differential diagnosis. Periodic sharp waves are seen in Creutzfeldt–Jakob Disease. EEG desynchronization is characteristic of REM sleep. An isoelectric EEG is observed in cases of brain death whereas alpha waves are normal findings during wakeful states.
A 35-year-old man undergoes extradural resection of the temporal mass depicted in the MR image
shown. Postoperatively, he has persistent right eye keratoconjunctivitis sicca (dry eye syndrome).
Which of the following nerves was most likely injured during surgery?
Answers:
A. Chorda tympani
B. Greater superficial petrosal nerve
C. Lesser petrosal nerve
D. Oculomotor nerve
E. Ophthalmic branch of trigeminal nerve
Greater superficial petrosal nerve
The greater superficial petrosal nerve’s (GSPN) fibers arise from the superior salivatory nucleus in the pontine tegmentum, are carried in the nervus intermedius before the joining the rest of the facial nerve. After passing through the geniculate ganglion and exiting the facial canal, these fibers become the GSPN. The GSPN traverses the floor of the middle temporal fossa and exists the skull through the vidian canal. The GSPN supplies parasympathetic innervation to the lacrimal gland and mediates reflexive tearing. Damage to this nerve results in keratoconjunctivitis sicca.
Despite reasonably good compliance with highly active antiretroviral therapy, a 56-year-old man
with HIV infection presents with a single generalized seizure and a mass lesion in his right frontal
lobe just deep to the grey-white junction. Which of the following therapies is most likely to interfere
with obtaining a diagnostic biopsy?
Answers:
A. Anti-retroviral therapy
B. Use of steroids
C. Penicillin
D. Use of Bactrim
E. Keppra
Use of steroids
Toxoplasmosis, progressive multifocal leukoencephalopathy, lymphoma cryptococcal abscess and TB all represent possible focal lesions in patients with HIV. Toxoplasmosis is the most common mass lesion in patients with, but this usually occurs when CD4 counts are <200. Lymphoma can occur in patients after their CD4 counts normalize which may be the case for this pateint. The use of steroids can occasionally mask the diagnosis of patients with primary CNS lymphoma. The other choices would not necessarily interfere with obtaining a diagnostic biopsy.
A 38-year-old man has a four-week history of headache and transient diplopia. Serum level of
prolactin is 3250 ?g/mL. All other laboratory and endocrine findings are within normal limits. Axial
and coronal T1 MR images are shown. Which of the following is the most appropriate next step in
management?
Answers:
A. Stereotactic radiosurgery
B. Carbergoline administration
C. Bromocriptine administration
D. Transphenoidal tumor resection
E. Dexamethasone suppression test
Carbergoline administration
The patient described here has a prolactinoma. Prolactinomas are the most common types of pituitary micro- and macroadenomas and result in the secretion of excess prolactin. Large prolactinomas may exert local mass effect and cause cranial neuropathies. Prolactinomas may also cause endocrinopathies manifesting as osteoporosis, amenorrhea, decreased libido, galactorrhea, decreased fertility, and erectile dysfunction. Prolactin secretion is normally negatively related by dopamine that is produced and secreted by the hypothalamus. For non prolactin secreting adenomas, serum prolactin levels may be elevated due to mass effect on the infundibular stalk (disinhibiting the effect of dopamine on prolactin secretion). If serum prolactin level is in excess of 200 μg/mL, this is almost always due to a prolactin secreting tumor—rather than due to stalk effect. Primary treatment involves the administration of a dopamine agonist. Carbergoline is preferred over bromocriptine as it is better tolerated with a more favorable side effect profile. Carbergoline treatment is effective at reducing excessive prolactin secretion and normalization of prolactinoma size. As prolactinomas respond well to medical therapy, transsphenoidal resection is only performed if medical therapy fails or in the setting of an acute neurologic deficit. The dexamethasone suppression test is utilized to establish a diagnosis of cortisol excess (Cushings syndrome). Stereotactic radiosurgery is utilized for pituitary adenomas that are otherwise not amenable to medical or surgical treatment. References:
Which of the following genetic features of a glioma carries a favorable prognosis?
Answers:
A. IDH1 mutation
B. EGFR amplification
C. P53 mutation
D. 1p19q intact
E. IDH1 wild type
IDH1 mutation
Various favorable prognostic factors for gliomas include IDH1/2 mutation and 1p19q codeletion. For glioblastomas, p53 wild-type status, EGFR non-amplification, O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, global DNA hypermethylation (e.g., G-CIMP phenotype), and TERT promoter wild-type status offer improved prognosis. Most low-grade gliomas without an IDH mutation are molecularly and clinically similar to glioblastoma.
A 13-year-old boy is found to have diabetes insipidus and intermittent headaches over a fourmonth period. He has no significant past medical or family history. His vision is intact and the remainder of his neurological examination is unremarkable. A T1-weighted sagittal MR image with contrast is shown. Which of the following is the most likely diagnosis? Answers:
A. Germinoma
B. Pineoblastoma
C. Lymphoma
D. Pineocytoma
E. CNS metastases of systemic malignancy
Germinoma
This patient has a moderately sized heterogenous lesion of the pineal gland and a smaller but radiographically similar appearing lesion of the sella and suprasellar area. Pineal germinomas are the most common pineal tumors and can occasionally be bifocal – in both the pineal region and suprasellar. In this patient with diabetes insipidus, this is the most likely diagnosis. Pineoblastoma and pineocytoma are less common pineal tumors and do not present with synchronous lesions to the pituitary gland. Metastasis and lymphoma are not impossible but this presentation is classic for bifocal germinoma so that is a better answer.
The patient whose MR images are shown has aspergillosis of the brain. Which of the following is
the most likely cause of the distant sites of acute infarcts?
Answers:
A. Venous infarctions
B. Thrombo-embolic infarcts
C. Charcot-Bouchard Aneurysms
D. Cerebritis
E. Infectious vasculopathy
Infectious vasculopathy
Aspergillus is a fungal infection that can cause infections within the lungs of several immunocompromised individuals. Hematologic spread to the brain is a common phenomenon in these individuals. Aspergillosis has an infinity to invade the vessel walls and eventually lead to destruction of the internal elastic lamina. As a result, aspergillus causes direct infection of the parent vessel. This is believed to cause occlusion of small perforators leading to infarctions that have been reported to occur frequently in the thalamus, basal ganglia, corpus callosum. This is unique and different than the mechanism observed in most hematogenous infections that reach the CNS (i.e septic emboli from infective endocarditis that typically can directly occlude a parent vessel leading to infarctions at the corticomedullary junction). Charcot-Bouchard Aneurysms – Are thought to result from chronic hypertension and have been postulated to lead to spontaneous intracerebral hemorrhages Venous infarctions can occur in the setting of a subdural empyema, not with aspergillosis Cerebritis – This is a non-specific term, but reflects inflammation of the brain, typically as a result of an infection
A 57-year-old man with diabetes mellitus is admitted to the hospital with symptoms of
leptomeningitis. Examination also reveals facial cellulitis and unilateral exophthalmos. The most
likely diagnosis is
Answers:
A. Herpes Zoster
B. Mollaret’s meningitis
C. Orbital cellulitis
D. Graves’ exophthalmos
E. Viral meningitis
Orbital cellulitis
The symptoms of facial cellulitis, leptomeningitis, and unilateral exophthalmos should raise suspicion for orbital cellulitis infection with intracranial progression. Diabetes mellitus predisposes patients to facial cellulitis which can progress to orbital cellulitis and cavernous sinus involvement with proptosis, edema of the conjunctiva, ophthalmoplegia, or decreased visual acuity. Herpes zoster is not associated with cellulitis. Although viral and Mollaret’s meningitis are not usually associated with facial cellulitis and exophthalmos. Graves’ disease is not associated with leptomeningitis and facial cellulitis
Which of the following tumors is most commonly found in the region of the filum terminale in
adults?
Answers:
A. Subependymoma
B. Chordoma
C. Myxopapillary Ependymoma
D. Meningioma
E. Lymphoma
Myxopapillary Ependymoma
Myxopapillary ependymoma arises almost exclusively from the region of the filum terminale and are the most common tumor in this area. Chordomas are tumors of the bone and generally are not intradural. Lymphoma and meningioma can both present as intradural tumors and can occur adjacent to the filum terminale although they are less common. Subependymoma is an intraventricular tumor and generally not found in the thecal sac.
A 63-year-old woman is evaluated because of diplopia. On examination of extraocular movement,
the patient has no horizontal left eye movement, is unable to adduct the right eye past midline, and
has nystagmus when abducting the right eye. The lesion causing these findings is most likely
found at which of the following locations?
Answers:
A. Internuclear ophthalmoplegia
B. 3rd nerve palsy
C. Weber syndrome
D. Oculomotor nuclei stroke
E. One and a half syndrome
One and a half syndrome
One and a half syndrome is an oculomotor weakness resulting in ipsilateral conjugate horizontal gaze palsy in one direction and an internuclear ophthalmoplegia. The ipsilateral eye is fixed straight ahead. The contralateral eye can be exotropic with abduction nystagmus. The syndrome arises from a lesion to the paramedian pontine reticular formation (PPRF) or abducens nucleus and ipsilateral medial longitudinal fasciculus (MLF). Convergence is spared as the oculomotor nerve and its nuclei bilaterally are spared. The most common causes are cerebrovascular disease, but other causes include infectious and demyelinating lesions.
A 12-year-old patient undergoes resection of a midline medulloblastoma. Which of the following
complications is most likely to occur?
Answers:
A. Cerebellar hemorrhage
B. Hydrocephalus
C. Cerebellar mutism
D. Unilateral abducens palsy
E. Bilateral dysmetria
Cerebellar mutism
Although the other listed complications can occur, cerebellar mutism is the most common complication after resection of midline cerebellar tumors. Most cases of mutism are due to injury of cerebellar tracts and cerebellar-cerebral circuits, involving particularly distinct points of the dentatethalamus-cortical and dentato-rubro-thalamus-cortical.
A previously healthy 56-year-old man has the sudden onset of painless loss of vision in the right
eye. On examination, he can see hand motion with the affected eye. Vision in the left eye is
unaffected. Funduscopic examination shows a cloudy whitening of the retina and a cherry red spot
in the macula. Which of the following is the most likely diagnosis?
Answers:
A. Abusive Trauma
B. Idiopathic intracranial hypertension
C. Sellar Tumor with suprasellar extension
D. Central Retinal Artery Occlusion
E. Tolosa Hunt Syndrome
Central Retinal Artery Occlusion
Cherry-red spot (CRS) at the macula is a clinically significant sign observed on fundus examination in a variety of pathological conditions, including retinal infarction, retinal ischemia. as well as a variety of lysosomal storage disorders. The term refers to the appearance of a red-tinted region at the center of the macula surrounded by retinal opacification Central retinal artery occlusion (CRAO) - This disease entity characteristically presents as a sudden onset of painless, unilateral visual loss in elderly patients, most commonly caused by an embolism, which blocks the central retinal artery. The embolus may be composed of cholesterol, fibrin-platelet, or calcium and usually originates from the carotid plaque and less commonly from the heart or the aorta. Inflammatory conditions like giant cell arteritis (GCA), may also cause CRAO. Other causes of CRAO include myxoma or vegetations of the cardiac valves, thrombophilic disorders, and retinal migraine.
Which of the following immunohistochemical markers is most accurate in diagnosing a central neurocytoma?
Answers:
A. S-100
B. GFAP
C. Synaptophysin
D. EMA
E. Chromogranin
Synaptophysin
Synaptophysin is a common marker of neuronal-derived neoplasms including gangliocytoma and ganglioglioma, and central neurocytoma. Chromogranin and GFAP can be found in central neurocytoma but not consistently. GFAP is more common in astrocytic tumors. Chromogranin is commonly seen in neuroendocrine tumors like paraganglioma. S-100 is seen in melanomas and schwannomas. EMA is common in meningiomas.
Which of the following is the most common neurological deficit in a patient with AIDS?
Answers:
A. Neurocognitive decline
B. Chorea
C. Seizures
D. Dystonia
E. Bell’s Palsy
Neurocognitive decline
There are direct neurologic manifestations that occur as a result of HIV infections that are independent of focal mass (i.e. toxoplasmosis abscesses, PML etc). It is estimated that between 20-50% of patients with HIV will develop HIV-associated neurocognitive decline (HAND). The incidence of HAND has not decreased with the improvement in the treatment of opportunistic infections and the implementation of highly active antiretroviral therapy. HAND is characterized by the slow progression of cognitive impairment and is a spectrum ranging from mild cognitive impairment to dementia. Alzheimer’s, cerebral small Bessel disease and other opportunistic infections remain in the differential diagnosis. The pathogenesis of HAND relates to early HIV infiltration of the brain leading to HIV encephalitis (characterized by macrophage and lymphocyte infiltration) followed by HIV leukoencephalopathy which is characterized by diffuse loss of myelin and astrocytosis. Dystonia and chorea are not typically associated with HIV. Bell’s palsy can be associated with HIV infection, but this is more typically seen in other infections such as Lyme’s disease. Seizures can result from local cortical irritation secondary to mass lesions within the brain, but is less common than HAND.
A 60-year-old woman is evaluated because of a four-month history of headaches. Physical examination shows a bitemporal hemianopia. Laboratory studies show an increased serum prolactin level at 90 ng/mL and normal thyroxine (T4), thyroid-stimulating hormone, folliclestimulating hormone, insulin-like growth factor, and cortisol (AM) levels. A T1-weighted MR image is shown. Which of the following is the most appropriate management?
Answers:
A. Bromocriptine
B. Octreotide
C. Tumor resection
D. Cabergoline
E. Radiation
Tumor resection
This patient has a large, symptomatic pituitary adenoma. Surgery is the best option to decompress the optic chiasm. Her prolactin is elevated but not to the level expected if this were a prolactinoma. The elevation is likely due to stalk effect from the tumor impairing the inhibitory dopaminergic signals from the hypothalamus on the prolactin-secreting anterior pituitary cells. A prolactin level 20-200 is typically due to stalk effect in the setting of a macroadenoma. Prolactinomas can be treated with bromocriptine. Cabergoline is used to treat numerous hormone secreting adenomas but most commonly prolactinomas. Octreotide is typically used to treat growth hormone secreting adenomas, which are typically microadenomas. Radiation would not be appropriate in a patient who already is experiencing visual symptoms.
A 9-year-old girl is evaluated because of a 3-day history of headache, nausea, vomiting, and
irritability. An MR image of the brain shows a mass in the posterior lateral ventricle.
Immunohistochemical staining of a biopsy specimen from the tumor is positive for cytokeratins,
vimentin, and S100 protein. Which of the following is the most likely diagnosis?
Answers:
A. Ependymoma
B. Central neurocytoma
C. Atypical Teratoid/rhabdoid tumor
D. Choroid plexus papilloma
E. Subependymoma
Choroid plexus papilloma
Choroid plexus papilloma virtually all express cytokeratins, vimentin, and podoplanin. S-100 is positive in a majority of tumors as well. Although it can present in this location, the classic marker for central neurocytoma is synaptophysin. Subependymoma and ependymoma are two other intraventricular tumors but are glial in origin and thus GFAP positive. Atypical teratoid/rhabdoid tumors are infrequently intraventricular. They can be vimentin and cytokeratin positive but are generally S100 negative.
Which of the following CNS-demyelinating diseases occurs in severely immunosuppressed patients and is caused by oligodendrocyte infection with the JC virus?
Answers:
A. Multiple Sclerosis
B. Progressive Multifocal Leukoencephalopathy (PML)
C. Acute Disseminated Encephalomyelitis
D. Charcot-Marie Tooth Disease
E. Transverse Myelitis
Progressive Multifocal Leukoencephalopathy (PML)
The JC virus is a polyomavirus that can infect oligodendrocytes within the central nervous system in severely immunocompromised individuals. As a result of the infection, progressive demyelination can occur. Most instances of PML are associated with HIV (55-85%) although PML can occur in patients with chronic lymphocytic leukemia, lymphoma or other immunocompromised states. Patients with PML can present with mental status changes, motor or sensory deficits. MR imaging is notable for hyper -intense T2WI lesions in the white matter (usually spares the grey matter) that lacks contrast enhancement. Transverse myelitis – is an inflammatory condition of the spinal cord with multiple etiologies including infectious (i.e. polio, herpes zoster), post-infectious (i.e. following influenza), traumatic, paraneoplastic, metabolic or autoimmune. Multiple Sclerosis – This is an autoimmune demyelinating condition. This is not caused by the JC virus. Charcot-Marie Tooth disease – This is an inherited, peripheral nervous system demyelinating condition. Acute Disseminated Encephalomyelitis (ADEM) – This is monophasic demyelinating condition that typically occurs in the setting of a recent vaccination
An internuclear ophthalmoplegia is localized to which of the following parts of the brain stem?
Answers:
A. Vertical gaze center
B. Oculomotor nuclei
C. Horizontal gaze center
D. Abducens nuclei
E. Medial longitudinal fasciculus
Medial longitudinal fasciculus
Internuclear ophthalmoplgia (INO) is an ocular movement disorder caused by a lesion of the medial longitudinal fasciculus (MLF) resulting in impaired ipsilateral adduction and nystagmus of the abducting eye. 30% of cases are due to infarction, 30% from demyelination, and the rest from a variety of infectious, iatrogenic or vascular reasons. Saccades are initiated by the frontal eye field which sends signals to the contralateral paramedian pontine reticular formation (PPRF) for horizontal saccades and rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) for vertical saccades. The PPRF activates the ipsilateral abducens nucleus signaling the lateral rectus along with the contralateral medial rectus subnucleus of the oculomotor nucleus through the MLF. Convergence can be preserved in some cases of INO which can help distinguish this injury from pseudo-INO diseases (e.g. 3rd nerve palsy, myasthenia gravis).
Pituitary apoplexy most commonly occurs
Answers:
A. Due to hemorrhage or infarction of a pituitary lesion
B. Due to laceration of the infundibular stalk in the setting of skull base fractures
C. Due to ischemic necrosis in the setting of medical treatment of Cushing’s disease
D. As a complication of transsphenoidal surgery of sellar lesions
E. Due to rupture of an inferiorly projecting anterior communicating artery aneurysm
Due to hemorrhage or infarction of a pituitary lesion
Pituitary apoplexy is a clinical syndrome defined as the neurologic and endocrinologic presentation of a patient who has suffered hemorrhage or infarction of a pituitary lesion with an incidence ranging of 0.6-13%. It is characterized by the acute onset of headache, nausea and emesis, visual nerve deficits, cranial neuropathies, and altered sensorium due to endocrinopathies. The benefits of medical management vs. early surgical treatment continues to be debated; though, patients presenting with cranial neuropathies may demonstrate clinical improvement with early surgical intervention. Laceration of the infundibular stalk results in diabetes insipidus. Crooke’s hyaline change refers to an increase in cytoplasmic keratin of the normal ACTH secreting pituitary cells in the setting of glucocorticoid excess. Rupture of anterior communicating artery aneurysms results in subarachnoid hemorrhage.
A 9-month-old boy who is breast-fed is evaluated for scaphocephaly. Length and weight are in the 10th percentile, although occipitofrontal circumference is in the 80th percentile. He has a history of gastroesophageal reflux disease that is treated with antacids. X-ray films confirm sagittal synostosis. Which of the following is the most likely diagnosis?
Answers:
A. Crouzon syndrome
B. Rickets
C. Vitamin A deficiency
D. Plagiocephaly
E. Carpenter syndrome
Rickets
Osteomalacia or rickets may result from altered 1,25-dihydroxyvitamin D bioavailability and/or deficiency of calcium or phosphorus. Moreovever, a rare but well-recognized cause of hypophosphatemia is the long-term ingestion of phosphate-binding aluminum- or magnesium- containing antacids. Antacids that contain aluminum or magnesium bind phosphate in the gut and result in markedly decreased phosphate absorption, leading to severe phosphate depletion. There is an increased risk of sagittal synostosis in hypophosphatemic rickets and related diseases in children. The appearance of the cranial vault in this type of synostosis can vary from that seen in nonsyndromic synostosis. In this setting, careful clinical and imaging follow-up is warranted.
A 60-year-old woman presents with left pulsatile tinnitus, trouble swallowing, and hoarseness. On examination, the uvula deviates to the right. The image shows the appearance of the left tympanic membrane on otoscopy consistent with the “Rising Sun” sign. Which of the following is the most likely diagnosis?
Answers:
A. Paraganglioma
B. Chordoma
C. Schwannoma
D. Dural AV Fistula
E. Cholesteatoma
Paraganglioma
This patient has pulsatile tinnitus, is showing signs of lower cranial nerve dysfunction and otoscopy reveals a “rising sun sign”. These findings are classic for a glomus tumor or paraganglioma. Paragangliomas are referred to as pheochromocytomas when they arise from the adrenal gland and are sometimes also called chemodectomas depending on their histologic morphology. The “Rising Sun” sign is the visualization of a red tumor along the floor of the middle ear and can be seen in a variety of otologic diseases. When blanchable, it is referred to as “Brown’s Sign” which is a specific finding for a glomus tympanicum tumor but can also be seen in glomus jugulare tumors. Cholesteatomas and schwannomas are tumors that can affect the middle ear but rarely cause lower cranial nerve dysfunction and are not associated with the Rising Sun sign. Chordomas of the skull base can cause lower cranial nerve dysfunction but usually not pulsatile tinnitus. Dural AV fistulas can cause pulsatile tinnitus but usually not other neurologic signs.
Of the answer choices listed, select the most likely associated disorder to cause ptosis, normal
pupil, diplopia, orbital pain.
Answers:
A. Tolosa Hunt Syndrome
B. Bells Palsy
C. Diabetes
D. Myasthenia Gravis
E. Aneurysm
Diabetes
Diabetic 3rd nerve palsies are the most common etiologic subset of 3rd nerve palsy in adults. Patients have pain and a pupil sparing 3 nerve palsy.
1. Ptosis: Due to paralysis of LPS (levator palpebrae superioris) muscle
2. 2. Ocular deviation: In case of third-nerve palsy, the lateral rectus and superior oblique are spared, and their unopposed action brings the eye in a “down and out” position.
3. 3. Pupil:In compressive third-nerve palsy, the pupil becomes fixed and dilated due to paralysis of sphincter pupillae. Ciliary muscle paralysis also leads to loss of accommodation. However, in ischemic lesions, the pupil is spared, and there is no loss of accommodation.
4. 4. Diplopia:This occurs due deviation of the affected eye resulting in the image falling on an extrafoveal point. However, due to ptosis the patient usually doesn’t complain of double vision as ptosis acts as a barrier to diplopia.
Tolosa Hunt Syndrome is also hallmarked by orbital pain, however typically there is pupillary involvement, and often more than one nerve in the cavernous sinus involved. Compression from an aneurysm would have pupil involved 3 rd nerve palsy.
Bells Palsy involves CN7 and would not cause Diplopia
MG causes bilateral ptosis and is not painful
Inferior petrosal sinus sampling is most effective in the preoperative workup for which of the
following purposes?
Answers:
A. Studying pituitary venous drainage in surgical planning
B. Diagnosis of Cushing’s Response
C. Diagnosis of pituitary macroadenoma.
D. Lateralization of ACTH production by pituitary microadenoma
E. Lateralization of cortisol production by pituitary microadenoma
Lateralization of ACTH production by pituitary microadenoma
Inferior petrosal sinus sampling (IPSS) involves sampling of ACTH levels from the petrosal veins that drain the pituitary gland and comparing ACTH levels with systemic blood levels to determine pituitary versus ectopic ACTH production. IPSS can be used to established lateralization (right versus left) of ACTH production which could guide surgical exploration when the microadenoma is not obvious on MRI.
The 35-year-old woman whose MR scan is shown has lesions in her eyes and kidneys and mild
right-sided cerebellar dysfunction. The most appropriate treatment of her focally enhancing lesion
is which of the following?
Answers:
A. Radiation
B. Bevacizumab
C. Resection of nodule
D. Minimally invasive cyst drainage
E. Observation
Resection of nodule
This patient has a cystic tumor of her posterior fossa. The lesions in her eyes and kidneys suggest she has von Hippel Lindau disease. This means the posterior fossa tumor is likely a hemangioblastoma which is symptomatic and should be resected. Observation is reasonable for smaller asymptomatic tumors in patients with VHL. Radiation is reserved for palliative cases. If the cyst is drained, it will likely recur as the underlying nodule continues to grow. Moreover, the nodule can be very vascular and minimally invasive drainage may result in hemorrhage. Bevacizumab is utilized for VHL patients with multiple lesions that are growing and not amenable to surgical resection.
A 5-year-old boy is scheduled to undergo a suboccipital craniotomy for resection of the large
posterior fossa tumor depicted in the MR image shown. Consent must be obtained for the
procedure. The parents should be counseled regarding which of the following risks to the child’s
speech and cognitive development after surgery?
Answers:
A. Anomia and finger agnosia
B. Cerebellar mutism
C. Temporary hemiparesis
D. Permanently impaired speech and cognition
E. Alexia without agraphia
Cerebellar mutism
Cerebellar mutism syndrome typically develops after resection of midline cerebellar or intraventricular tumors in the posterior fossa (as shown in the image). The constellation of symptoms includes transient mutism, ataxia, hypotonia and irritability. This typically occurs in children, although there are reports of cerebellar mutism occurring in adults. Cerebellar mutism is thought to occur due to post-surgical injury to the dentato-thalamo-cortical tract. Supportive care and early rehabilitation are critical for recovery. Anomia and finger agnosia are characteristic of Gerstmann’s Syndrome, resulting from dominant parietal damage. Temporary contralateral hemiparesis would be consistent with SMA syndrome. Alexia without agraphia is a type of disconnection syndrome, which can be caused by posterior corpus callosum damage.
Which of the following is the most common cause of a pupil-sparing oculomotor nerve palsy?
Answers:
A. Tolosa Hunt Syndrome
B. Bell’s Palsy
C. Diabetes
D. Aneurysm
E. Myasthenia Gravis
Diabetes
Diabetes mellitus and hypertension cause ischemic changes in the nerve and are the most common systemic causes of acquired nerve palsy
1. Ptosis: Due to paralysis of LPS (levator palpebrae superioris) muscle
2. Ocular deviation: In case of third-nerve palsy, the lateral rectus and superior oblique are spared, and their unopposed action brings the eye in a “down and out” position.
3. Pupil: In compressive third-nerve palsy, the pupil becomes fixed and dilated due to paralysis of sphincter pupillae. Ciliary muscle paralysis also leads to loss of accommodation. However, in ischemic lesions, the pupil is spared, and there is no loss of accommodation.
4. Diplopia: This occurs due deviation of the affected eye resulting in the image falling on an extrafoveal point. However, due to ptosis the patient usually doesn’t complain of double vision as ptosis acts as a barrier to diplopia.
Following surgical resection of glioblastoma, standard therapy includes radiotherapy with
concomitant and adjuvant temozolomide. What is the standard radiation dose given in 30
fractions?
Answers:
A. 30 Gy
B. 40 Gy
C. 25 Gy
D. 60 Gy
E. 24 Gy
60 Gy
In Stupp et al. published in the NEJM in 2005, it was found that fractionated focal radiation at a dose of 2 Gy per fraction given one daily for five days per weeks over a period of six weeks, for a total of 60 Gy with concomitant chemotherapy consisting of temozolomide demonstrated a clinically meaningful and statistically significant survival benefit compared to radiotherapy alone. Among elderly patients, there is no evidence that conventionally fractionated radiation therapy (60 Gy in 30 fractions) is more efficacious than hypofractionated radiation therapy (eg, 40 Gy in 15 fractions over 3 weeks). Compared with conventionally fractionated radiation therapy, hypofractionated radiation therapy has been associated with superior survival and less corticosteroid requirement.
The patient with the lesion shown in Figures 1 and 2 is at greatest risk for which of the following
neurological deficits postoperatively?
A. Expressive aphasia
B. Seizures
C. Short term memory loss
D. Disconnection syndrome
E. Mutism
Short term memory loss
The figure demonstrates a non-enhancing lesion in the roof of the third ventricle blocking the bilateral foramen of Monroe. CT imaging demonstrates hyperdensity. This is most consistent with a colloid cyst. The most common complication encountered post operatively is short term memory loss. This is due to proximity of the fornix to the cyst, which can be injured during resection. Often the memory loss is transient and returns within months after surgery. Expressive aphasia can occur from injury to the dominant inferior frontal lobe cortex. Seizures can occur from irritation to the brain secondary to open surgery. Mutism can occur following extensive injury to the corpus callosum. Disconnection syndrome can occur secondary to injury of the corpus callosum as a result of an interhemispheric approach to this lesion.
A 45-year-old woman presents to the emergency department because of sudden onset of
headaches, right ptosis, and bilateral blurred vision. T1-weighted sagittal (Figure 1), T1-weighted
coronal (Figure 2), and T2-weighted coronal (Figure 3) MR images are shown. Which of the
following is the most appropriate treatment option?
Answers:
A. Repeat MRI in 2 weeks
B. Immediate transsphenoidal resection
C. Stereotactic radiosurgery
D. Treatment with dopamine agonist
E. Placement of external ventricular drain
Immediate transsphenoidal resection
The MRI images demonstrate evidence of pituitary apoplexy with significant expansion of the adenoma with compression of the optic chiasm cephalad and extension into the right cavernous sinus resulting in presentation of visual deterioration and ophthalmoplegia. Pituitary apoplexy defines hemorrhage or infarction of a preexisting pituitary adenoma resulting in rapid expansion of contents of the sella turcica. It can result in a classical constellation of symptoms characterized by sudden severe headaches, visual impairment, ophthalmoplegia, vomiting, and altered mental status. Hemodynamic stabilization with corticosteroid and necessary hormonal replacement followed by surgical decompression has been considered generally to be the best treatment course for apoplexy that results in neuro-ophthalmologic symptoms. There is controversy regarding the timing of surgery whether immediate decompression is necessary for the highest chance to restore neurological function, or surgery in the subacute period can also provide the same benefit. Most studies agree that surgical decompression within the subacute period (< 6-7 days) have the same overall outcome and chance for neurological recovery. In the absence of neurological deficits, conservative management may achieve similar results.
A patient has homogeneously enhancing lesions in both the pineal and the suprasellar regions.
Which of the following is the most likely diagnosis?
Answers:
A. Meningioma
B. Glioblastoma
C. Germinoma
D. Pineoblastoma
E. Arachnoid Cyst
Germinoma
Intracranial germinomas, also known as dysgerminomas or extra-gonadal seminomas, are a type of germ cell tumor and are predominantly seen in pediatric populations. They tend to occur in the midline, either at the pineal region (majority) or along the floor of the third ventricle/suprasellar region. The differential diagnosis for a pineal tumor is broad and includes tumors of pineal (pinealocytoma, pineoblastoma), germ cell (germinoma, embryonal carcinoma, endodermal sinus, choriocarcinoma, teratoma), glial (astrocytoma, glioblastoma, ependymoma, choroids plexus papilloma, etc.), and other (meningioma, dermoid, epidermoid, or arachnoid cyst) derivations. However, a synchronous pineal region and suprasellar tumor (as seen in this patient) is considered almost pathognomonic of a germinoma. Germinomas are tumors of young patients with a peak incidence of 10-12 years of age (90% of patients being younger than 20 at the time of diagnosis). They account for 3-5% of pediatric intracranial tumors but only 0.4-1% of intracranial tumors in adults. They are the most common tumor of the pineal region accounting for approximately 50% of all tumors, and the majority (73-86%) of intracranial germ cell tumor. Gender ratios are interestingly different depending on location. In the pineal region there is a marked male preponderance with a male to female ratio of 5-22:1 whereas in the suprasellar region, they are slightly more frequent in females with a male to female ratio of 1:1.3. Overall, due to the pineal region being most common, germinomas are seen more frequently in males. Presentation depends on location, with compression of the tectal plate leading to obstructive hydrocephalus and Parinaud syndrome, whereas involvement on the pituitary infundibulum leads to diabetes insipidus (most common), hypopituitarism (common) or optic chiasm compression or signs of intracranial hypertension. When the thalami and basal ganglia are involved, the presentation is often delayed with a larger tumor at diagnosis. Pure germinomas are commonly highly radiosensitive and are often treated without total surgical resection.
The neoplasm that commonly displays either estrogen or progesterone receptors is which of the following?
Answers:
A. Glioblastoma
B. Hemangiopericytoma
C. Schwannoma
D. Meningioma
E. Medulloblastoma
Meningioma
Meningiomas can be positive for estrogen and progesterone receptors. Hemangiopericytomas can mimic meningioma but are hormone receptor negative. Many other CNS neoplasms can express hormone receptors including schwannoma, glioblastoma, and medulloblastoma but these are not markers typically used to identify these tumors.
Unilateral pulsatile exophthalmos is characteristic of which of the following conditions?
Answers:
A. Graves Disease
B. Carotid cavernous fistula
C. Hypothyroidism
D. Tolosa Hunt Syndrome
E. Orbital infection
Carotid cavernous fistula
Carotid cavernous fistula (CCF) is an abnormal communication between the cavernous sinus and the carotid arterial system. Patients with CCF may initially present to an ophthalmologist with decreased vision, conjunctival chemosis, external ophthalmoplegia and proptosis. Graves disease is the most common cause of exophthalmos, however it is bilateral and non pulsatile. An orbital tumor could be a cause of pulsatile exophthalmos.
A 61-year-old man undergoes resection of a 3.5-cm glioblastoma with 99% extent of resection. He
is neurologically intact and has a postoperative Karnofsky Performance Status score of 80. Which
of the following is the most appropriate selection for postoperative adjuvant radiotherapy in this
patient?
Answers:
A. 34 Gy in 10 fractions
B. 24 Gy in 1 fraction
C. 25 Gy in 5 fractions
D. 40Gy in 15 fractions
E. 60Gy in 30 fractions
60Gy in 30 fractions
In Stupp et al. published in the NEJM in 2005, it was found that fractionated focal radiation at a dose of 2 Gy per fraction given one daily for five days per weeks over a period of six weeks, for a total of 60 Gy with concomitant chemotherapy consisting of temozolomide demonstrated a clinically meaningful and statistically significant survival benefit compared to radiotherapy alone. Among elderly patients, there is no evidence that conventionally fractionated radiation therapy (60 Gy in 30 fractions) is more efficacious than hypofractionated radiation therapy (eg, 40 Gy in 15 fractions over 3 weeks). Compared with conventionally fractionated radiation therapy, hypofractionated radiation therapy has been associated with superior survival and less corticosteroid requirement.
A 22-year-old woman is evaluated for a six-month history of progressive headaches, blurred
vision, weakness, and balance difficulties. A contrast-enhanced sagittal MR image of the brain
stem and cervical cord is shown. A CT scan of the chest is unremarkable, and an abdominal CT
scan shows a hypervascular adrenal lesion. Which of the following is the most likely genetic basis
for the observed findings?
Answers:
A. Autosomal dominant
B. Autosomal recessive
C. Chromosomal translocation
D. Isolated genetic mutation
E. X-linked inheritance
Autosomal dominant
This patient most likely has von Hippel Landau (VHL) disease, which demonstrates autosomal dominant inheritance based on a gene mutation found on chromosome 3. VHL is caused by a mutation of the tumor suppressor gene (pVHL). Patients with his condition have tumors that can arise in multiple organs. Most commonly, they have hemangioblastomas. Approximately 25-33% of patients harboring a hemangioblastoma have Von Hippel-Lindau disease. These lesions are highly vascular, and their removal requires meticulous dissection and cautious circumferential disruption of feeding arteries and draining veins. People with VHL can also have retinal angiomas, clear cell renal cell carcinoma, pancreatic neuroendocrine tumors and pheochromocytomas, which is likely the hypervascular adrenal lesion in this case. This patient has a hemangioblastoma of the spinal cord and posterior fossa. These are brightly enhancing lesions. These lesions usually have distinct borders between tumor and spinal cord. They may be cured by total surgical excision. Therefore, external beam radiotherapy or, conversely, conservative management are not indicated. Open biopsy is an option, but once the diagnosis of hemangioblastoma is confirmed, gross total excision should be undertaken.
A 41-year-old man is diagnosed with a 3.2-cm prolactinoma and initiated on cabergoline therapy with good response. Two months later, he presents to the emergency department (ED) with sudden-onset headache and decreased vision. He has an episode of mild hypotension in the ED. Visual acuity is 20/400 in both eyes (previously 20/30). CT scan and laboratory values are shown. In chronological order, the most appropriate next steps in management would be which of the following?
Answers:
A. Hormonal (thyroid and adrenal) supplementation followed by transsphenoidal resection.
B. Hormonal (thyroid and adrenal) supplementation alone.
C. Increase the dose of cabergoline since the original tumor responded to cabergoline.
D. Cabergoline plus transsphenoidal surgery
E. Transsphenoidal surgery alone
Hormonal (thyroid and adrenal) supplementation followed by transsphenoidal resection.
The presentation of acute vision loss and panhypopituitarism in the setting of known prolactinoma should raise suspicion for pituitary apoplexy. In addition, the presence of adrenal insufficiency with hypotension should suggest potential Addisonian crisis. The appropriate management would entail immediate adrenal and thyroid hormonal supplementation followed by sellar decompression if there is chiasmatic compression from hemorrhage.
A 68-year-old man with a history of colon cancer is evaluated for gait disturbance. The MR image
shown depicts a 3.5-cm lesion in the right cerebellar hemisphere. Which of the following treatment
strategies is supported by level I evidence to maximize local control and improve survival for this
patient?
Answers:
A. Stereotactic radiosurgery
B. Surgery and stereotactic radiosurgery
C. Surgical resection and whole brain radiation therapy
D. Whole brain radiation therapy
E. Leucovorin, fluorouracil, and oxaliplatin
Surgical resection and whole brain radiation therapy
The image depicts a right sided cerebellar lesion with significant mass effect to the adjacent brain parenchyma and compression on the Aqueduct of Sylvius. The patient’s history of colon cancer makes this likely to be a metastatic tumor. Level I evidence exists that for single brain metastases larger than 3 to 4 cm and amenable to safe complete resection, with favorable performance status and limited extracranial disease, surgery and whole brain radiation provides maximum local control and improvement of survival. Level I evidence demonstrates that surgery and whole brain radiation therapy is superior to WBRT alone in patients with single metastasis. Level III evidence indicates that surgery with stereotactic radiosurgery can provide survival benefit. Radiosurgery has been shown by Class I studies to extend survival in patients with metastatic brain tumors. In particular, radiosurgery with or without whole brain radiotherapy has been shown to extend survival 8-10.6 months (Aoyama et al). Routine use of chemotherapy following WBRT for brain metastases has not been shown to increase survival and is not recommended.
Which of the following is the most likely location of the lesion in the patient whose visual fields are
shown?
Answers:
A. Optic Nerve
B. Frontal Lobe
C. Optic chiasm
D. Optic Tract
E. Temporal Lobe
Temporal Lobe
Homonymous superior quadrantanopia, also called “pie in the sky,” causes a field deficit in the superior field of both eyes for the same side. Temporal lobe surgery (surgery beyond 3 cm of the temporal lobe usually produces a superior quadrantanopsia, while surgery beyond 8 cm usually will produce complete homonymous hemianopia). Between 89%-91% of the patients have a deficit; those with selective amygdalohippocampectomy less pronounced than those with standard temporal lobectomy
A 58-year-old man presents with gait imbalance. A coronal T1-weighted MRI with gadolinium is
shown in Figure 1. A right suboccipital craniotomy is performed. Upon entering a large right
cerebellar cyst, a cherry red nodule is seen along the cyst wall as shown in Figure 2. Which of the
following is the most likely diagnosis?
Answers:
A. Abscess
B. Hemangioblastoma
C. Ganglioglioma
D. Pleomorphic xanthoastrocytoma
E. Medulloblastoma
Hemangioblastoma
Hemangioblastoma, pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and ganglioglioma all cause cysts with mural nodules but gangliogomas and PXAs are typically supratentorial so hemangioblastoma is the best answer. Medulloblastoma typically cause more heterogenous lesions, not cysts with mural nodules. Abscesses are usually ring enhancing without nodularity. Hemangioblastomas are characterized by neoplastic stromal cells with high vascularity and are commonly found in the cerebellum, brainstem or spinal cord. They are WHO grade I tumors and can be associated with von Hippel-Lindau (VHL) disease.
A 45-year-old woman is evaluated for progressive weight gain, central obesity, moon facies, and
insulin-resistant type 2 diabetes mellitus. She is neurologically intact. An MR image of the brain is
shown. Chest x-ray film shows a small lung mass. Which of the following is the most appropriate
initial test to diagnose this patient’s endocrine condition?
Answers:
A. 24-Hour urinary free cortisol assay
B. Inferior petrosal sinus sampling
C. Cosyntropin (ACTH) stimulation test
D. Surgical biopsy
E. Dexamethasone suppression test
24-Hour urinary free cortisol assay
This is a patient the clinical features of Cushing’s syndrome. This occurs when the body has an
excess of cortisol. Common symptoms include weight gain, moon facies, buffalo hump, abdominal
striae, and thinned/fragile skin. Measurement of 24-hour urine free cortisol level is the preferred
screening test for Cushing’s syndrome.
In this patient, the MRI localizes a microadenoma. Therefore, there is no need for any further
testing such as inferior petrosal sinus sampling. The treatment of choice is surgery, as complete
resection results in chemical cure.
A 33-year-old woman presents with irregular menses. Her prolactin level is 48.9 ng/mL. Physical
examination shows a bitemporal hemianopia. MR images of the sella are shown. Which of the
following is the most appropriate therapeutic intervention?
Answers:
A. Radiotherapy to pituitary tumor
B. Medical treatment for prolactinoma
C. Transsphenoidal surgery for tumor resection
D. Close surveillance MRI observation
E. Craniotomy for interhemispheric resection of tumor.
Transsphenoidal surgery for tumor resection
Patient presents with a likely nonfunctioning pituitary macro-adenoma with vision loss consistent with chiasmatic compression. The most appropriate intervention would be tumor resection and decompression of the sellar via a transsphenoidal approach as opposed to interhemispheric approach. The mild elevation of prolactin is likely stalk effect as opposed to prolactinoma hence medical therapy would not be effective. Radiotherapy is not indicated in this setting of vision loss and chiasm compression. References:
A 20-year-old man is evaluated because of a two-year history of headaches. Neurological
examination shows normal findings. A T1-weighted contrast MR image and an intraoperative
photograph are shown. Which of the following postoperative complications is most likely to occur
with excision of this lesion?
Answers:
A. Bacterial meningitis
B. Aseptic meningitis
C. Deep vein thrombosis
D. Subtotal resection
E. Akinetic mutism
Aseptic meningitis
This posterior fossa tumor has a pearly-white appearance which is classic for an epidermoid. Resection of epidermoid cysts is associated with aseptic, or chemical meningitis. Bacterial meningitis, subtotal resection, and deep vein thrombosis are risks with any brain surgery but are much less common than aseptic meningitis for these patients. Akinetic mutism can rarely occur after posterior fossa surgery if a transvermian approach is taken to the fourth ventricle However, the operative image shows an infracerebellar telovelar approach is being used so akinetic mutism is unlikely.
An 84-year-old man is evaluated because of diminished hearing in the left ear. The MR image
shown depicts an enhancing lesion in the left auditory canal. Which of the following is the most
appropriate next step in the management of this patient?
Answers:
A. Surgical removal via a translabyrinthine approach
B. Surgical removal via a restrosigmoid approach
C. Stereotactic radiosurgery in 3-5 fractions
D. Stereotactic radiosurgery in a single session
E. Reassurance and follow-up MRI in 6 months
Reassurance and follow-up MRI in 6 months
Reassurance and follow-up MRI are most appropriate. Most vestibular schwannomas grow at a slow rate. In an elderly patient who demonstrates an intracanalicular acoustic neuroma, the tumor can be followed with serial MR imaging until there is demonstrable growth. If an acoustic neuroma progresses in an elderly patient, stereotactic radiosurgery can often times be employed to inactivate the tumor cells. Long-term control of growth in acoustic neuromas following radiosurgery is greater than 90%. Immediate resection either via a retrosigmoid or translabyrinthine approach in elderly patients can be associated with higher complication rates, and these risks would likely outweigh the benefits especially in the setting of this small of tumor.
A 14-year-old girl is evaluated because of a several-month history of headaches and blurry vision.
A contrast-enhanced MR image of the brain is shown. Which of the following is the most likely
diagnosis?
Answers:
A. Turcot Syndrome
B. Von Hippel-Lindau disease
C. Neurofibromatosis Type 2
D. Cowden disease
E. Tuberous sclerosis
Von Hippel-Lindau disease
This patient has an enhancing tumor of her posterior fossa. Von Hippel-Lindau disease is associated with hemangioblastomas which are typically cystic tumors of the posterior fossa with an enhancing nodule. VHL results from a germline mutation in the VHL tumor suppressor gene on chromosome 3 and is an autosomal dominant condition. Patients may also have retinal hemangioblastoma, head/neck paragangliomas, renal cell carcinoma or cysts, pheochromocytoma, pancreatic cysts, endolymphatic sac tumors of the inner ear, papillary cystadenomas of the epididymis and broad ligament cystadnomas. Turcot syndrome can be associated with glioblastoma or medulloblastoma, but this tumor does not appear heterogenous as one would expect for glioblastoma or medulloblastoma. Neurofibromatosis type 2 is associated with schwannomas and meningiomas which are extraaxial tumors. Cowden disease is associated with Lhermitte-Duclos which is a dysplastic gangliocytoma of the cerebellum which is bright on T2 but usually does no enhance. Tuberous sclerosis causes subependymal giant cell astrocytoms and hamartomas. SEGAs are typically intraventricular and hamartomas do not enhance.
A 64-year-old man is evaluated because of a bitemporal hemianopia. MR imaging shows a
suprasellar mass consistent with a craniopharyngioma. A right orbitofrontal craniotomy is
performed to remove the tumor. In the intraoperative photomicrograph of the suprasellar region
shown, the craniopharyngioma can be seen between the optic nerves. Which of the following
structures is indicated by the asterisk?
Answers:
A. Oculomotor nerve
B. Left Internal Carotid Artery
C. Pituitary gland
D. Pituitary stalk
E. Left Anterior Cerebral Artery
Left Internal Carotid Artery
The image demonstrates the surgical view from a right orbitofrontal craniotomy. The craniopharyngioma can be seen between the optic nerves. On the ipsilateral side, the optic nerve can be seen just medial to the internal carotid artery. Just inferior to the contralateral optic nerve, the asterisk is marking the contralateral internal carotid artery. The anterior cerebral arteries would be just under the retractor. The pituitary stalk and gland are obscured by the mass itself which is filling the sella. The oculomotor nerve is not visible in this photo.
A 55-year-old woman is evaluated because of a one-year history of hearing loss, poor balance,
and dizziness. MR images of the brain are shown. An operation is performed, and multiple periods
of asystole occur during the tumor dissection. Which of the following reflexes is the most likely
cause of the intraoperative asystole?
Answers:
A. Vago-glossopharyngeal reflex
B. Cushing reflex
C. Oculocardiac reflex
D. Vaso-vagal reflex
E. Trigemino-cardiac reflex
Trigemino-cardiac reflex
The figure demonstrates an enhancing right sided cerebellopontine angle lesion with extension into the right internal acoustic canal. Along with the patient’s auditory and vestibular symptoms, this lesion is consistent with a vestibular schwannoma. The reflex ilicited is the trigemino-cardiac reflex (TCR). The TCR is a sudden onset of parasympathetic dysrhythmias including hemodynamic irregularities, apnea, and gastric hypermotility during stimulation of the sensory branches of the trigeminal nerve. The afferent limb is the trigeminal nerve, with the vagus nerve as the efferent limb. The TCR has been found to occur during craniofacial surgery, balloon-compression rhizolysis of the trigeminal ganglion, and tumor resection in the cerebellopontine angle, cavernous sinus, and the sella. The glossopharnygel-vagal reflex is bradycardia and asystole from irritation to the glossopharyngeal nerve. The oculocardiac reflex is moderate trigemino-vagal bradycardia that is elicited by tenson on an extraocular muscle. The vaso-vagal response is arteriolar dilation and cardiac slowing secondary blood loss or emotional stress. The Cushing reflex results in increased blood pressure, irregular breathing, and bradycardia, and is a response to increased intracranial pressure.
A 14-year-old boy is evaluated for a three-week history of progressive headache and visual
scotoma. An MR image is shown. Which of the following is the most likely diagnosis?
Answers:
A. Ependymoma
B. Pilocytic astrocytoma
C. Germinoma
D. Pineocytoma
E. Medulloblastoma
Germinoma
This patient’s imaging findings are most consistent with a germinoma, which typically appears as a solid contrast enhancing mass on CT/MR in the pineal region (and/or the hypothalamic region). Furthermore, germinomas are often described as engulfing the pineal gland, which gives the appearance of central calcification. The differential diagnosis of pineal region masses includes Germ Cell Tumors (~75% of all pediatric cases), Pineal Parenchymal Tumor (~25% of all pediatric cases), PNET, or Glioma. Germinoma is the most common (~50%) of the germ cell tumors. Unlike most CNS tumors, germ cell tumors may be associated with elevations in CSF levels of alpha-Fetal Protein (aFP), betahuman-Chorionic Gonadotropin (bhCG), and placental-like alkaline phosphatase (PLAP). Germinoma is associated with increased PLAP, and possible changes in bhCG. Large increases in bhCG are seen with choriocarcinoma, and elevations of aFP are seen with yolk-sac (endodermal sinus) tumor. Pilocytic astrocytomas. Ependymomas, and medulloblastomas are brain tumors that present in the pediatric population, but are not commonly located in the pineal region.
A left pterional craniotomy is performed to expose a small but growing left anterior clinoid meningioma as shown in Figure 1. The entire meningioma and the involved dura are removed. The bone of the anterior clinoid and the proximal optic canal underlying the meningioma are drilled away as shown in Figure 2. Which of the following Simpson grade resections of the meningioma was performed?
Answers:
A. Grade 4
B. Grade 5
C. Grade I
D. Grade 3
E. Grade 2
Grade I
The Simpson grading scale was developed in 1957 by Donald Simpson. It is the gold standard for defining the surgical extent of resection of WHO grade I meningiomas. The grading system was developed primarily to predict recurrence based on the extent of tumor resection. Recent reports have challenged the applicability of the scale to the modern approach to meningiomas.
Grade I is defined by a complete macroscopic resection of the tumor with removal of affected bone and dura.
Grade II is complete macroscopic resection of the tumor with coagulation of the affected dura.
Grade III is complete macroscopic resection of the tumor only.
Grade IV is subtotal tumor resection.
Grade V is decompression of the tumor with or without a biopsy.
A 57-year-old man is referred to the office because of a four-week history of suboccipital
headaches, gait ataxia, and nausea. A contrast-enhanced MR image is shown demonstrating a
contrast-enhancing nodule with adjacent cystic, fluid-filled lesion. Which of the following is the
most likely finding on physical examination?
Answers:
A. Retinal angioma
B. Hyperpigmentation
C. Facial malar rash
D. Shagreen patch
E. Subaxial freckling
Retinal angioma
Von Hippel Lindau (VHL) disease results from VHL mutation and is associated with hemangioblastomas of the brain, spinal cord and retina; renal cysts and clear cell renal cell carcinoma; pheochromocytoma, pancreatic cysts, and neuroendocrine tumors; endolymphatic sac tumors; and epididymal and broad ligament cysts. Renal cell carcinoma occurs in about 70% of individuals with VHL and is the leading cause of mortality. Cutaneous manifestations in VHL are rare. The vast majority of cerebellar hemangioblastomas are sporadic with about 20% related to familial VHL. Standardized guidelines govern the screening, genetic testing and surveillance of patients with VHL syndrome.
A 5-year-old girl with neurofibromatosis type 1 is referred because of the abnormal findings on the
MR images shown demonstrating a focal T2 hyperintensity within the brainstem. Physical and
neurological examinations show no abnormalities. Which of the following is the most appropriate
management?
Answers:
A. Laser interstitial thermal therapy
B. Stereotactic lesion biopsy
C. Chemotherapy and stereotactic radiosurgery
D. Stereotactic radiosurgery
E. Clinical observation
Clinical observation
Neurofibromatosis type 1 (NF1) is clinically defined by the presence of two or more of the following (Arch Neurol 1988;45:575-578): 1) 6 or more café-au-laut macules over 5 mm in diameter in prepubertal individuals and over 15mm in greatest diameter in postpubertal individuals; 2) Two or more neurofibromas of any type or one plexiform neurofibroma; 3) Freckling in the axillary or inguinal regions; 4) Two or more Lisch nodules (iris hamartomas); 5) Optic glioma; 6) A distinctive osseous lesion such as sphenoid dysplasia or thinning of long bone cortex, with or without pseudarthrosis; 7) First-degree relative (parent, sibling, or offspring) with NF-1 by the above criteria. Genetic testing can also be diagnostic. Patients with NF1 can present with brainstem gliomas however in many cases these can be observed and only treated if they become symptomatic. A series of 133 patients with NF1 at 4 major U.S. centers showed that the majority (54%) were asymptomatic at presentation and most were untreated (88%). Only 9 of 72 asymptomatic patients received treatment due to tumor enlargement. In contrast, 61 patients presented with focal neurological deficits and underwent treatment. These were more likely to be older children and those with focal lesions. Progression free survival was about 3 years shorter for the treated group. Overall survival was 85% for the tumor treated group and 100% for the untreated group.
A 45-year-old man is evaluated for several months of progressive headaches. MR imaging shows an intracranial lesion. Following surgical resection, histopathologic analysis shows a wellcircumscribed, uniformly cellular tumor with no atypia and numerous ectatic, thin-walled branching vessels in staghorn configurations. Which of the following is a possible associated clinical development?
Answers:
A. Bilateral vestibular schwannomas
B. Metastasis outside the CNS
C. De novo glioblastoma
D. Pheochromocytoma
E. Unilateral optic nerve glioma
Metastasis outside the CNS
The MRI demonstrates a well circumscribed lesion with homogenous enhancement. The pathology findings , particularly the ‘staghorn’ vasculature, indicate the diagnosis of hemangiopericytoma. The most common associated clinical development of hemangiopericytoma is metastasis outside the CNS. Hemangiopericytoma is a rare, aggressive central nervous system tumor that tends to invade locally and metastasize, and has a high rate of recurrence. 20-50% metastasize to lungs, liver, or bone. On histopathology, tumors are uniformly cellular (similar to cellular areas of solitary fibrous tumor) with numerous, variably ectatic or compressed, thin-walled branching vessels with gaping sinusoidal spaces (staghorn configuration). Tumor cells are spindled to round with small amounts of pale or eosinophilic cytoplasm, indistinct margins, bland vesicular nuclei. Reported 5-year overall survival is 86%. Pheochromocytoma are associated with MEN-2 syndrome and glomus jugularae tumors. Bilateral vestibular schwannomas are associated with neurofibromatosis-2 (NF-2).Hemangiopericytoma are rarely associated with NF-2. Unilateral optic nerve glioma is associated with neurofibromatosis-1. De novo glioblastoma are not associated with hemangiopericytomas.
A previously asymptomatic 44-year-old man is brought to the emergency department with suddenonset headache and blindness. Prolactin level is 1200 ng/mL. Pre- (Figure 1) and post-gadolinium (Figure 2) coronal MR imaging is performed, and the images shown are obtained. Which of the following is the most appropriate next step in management? Answers:
A. Initiate medical therapy with bromocriptine
B. Initiate medical therapy with cabergoline
C. Transsphenoidal or transcranial resection/decompression of the sellar
D. Observe and repeat MRI in 2 weeks
E. Stereotactic radiosurgery
Transsphenoidal or transcranial resection/decompression of the sellar
The presentation of acute blindness in the setting of hemorrhagic infarction of known pituitary tumor is consistent with pituitary apoplexy. This is a neurosurgical emergency since restoration of vision is a key goal. The most appropriate intervention would be sellar decompression. In addition, medical management for cortisol and thyroid supplementation is important.
A 58-year-old woman undergoes a right posterior transpetrosal approach for a petroclival
meningioma. A mastoidectomy followed by a supra and infratentorial craniotomy is performed. The
intraoperative photograph shown was obtained during the approach prior to opening the dura.
Which of the following letters in the photograph best approximates where the vein of Labbé enters
the transverse venous sinus?
Answers:
A. Location E
B. Location B
C. Location A
D. Location D
E. Location C
Location B
This image shows a craniotomy with a mastoidectomy. The mastoid was where the “D” is located. Just below the “D” is the sigmoid sinus and between “B” and “E” is the transverse sinus. The superior petrosal sinus is just to the right of “A”. The vein of Labbe typically drains into the transverse sinus although it can drain into the superior petrosal sinus. This area is most closely approximated by “B”. Care must be taken to preserve the drainage of Labbe to prevent venous infarction.
