Neuropathology Practice Questions

Q: Which of the following genetic syndromes are associated with brain tumours? 1. Neurofibromatosis type 1 2. Neurofibromatosis type 2 3. Tuberous sclerosis 4. Wiskott-Aldrich syndrome Select the answer using the code given below.

1, 2 and 3. ***1, 2 and 3*** - **Neurofibromatosis type 1 (NF1)**, **Neurofibromatosis type 2 (NF2)**, and **Tuberous sclerosis (TSC)** are all well-established genetic syndromes associated with an increased risk of developing various brain tumors [1]. - NF1 is linked to **optic pathway gliomas**, NF2 to **schwannomas** and **meningiomas**, and TSC to **subependymal giant cell astrocytomas (SEGAs)** [1], [2]. *1 and 2 only* - This option is incomplete as it correctly identifies NF1 and NF2 but omits Tuberous sclerosis, which is also strongly associated with brain tumours [1]. - While NF1 and NF2 are major genetic risk factors for brain tumors, excluding TSC would be an inaccurate representation of conditions linked to these abnormalities [1]. *1, 3 and 4* - This option incorrectly includes **Wiskott-Aldrich syndrome (WAS)**, which is an **immunodeficiency disorder** and not typically associated with primary brain tumours. - Although WAS can lead to an increased risk of lymphomas, these are generally not considered primary brain tumors [1] in the context of genetic syndromes predisposing to such growths. *2, 3 and 4* - This option again incorrectly includes **Wiskott-Aldrich syndrome** while omitting **Neurofibromatosis type 1**, a significant genetic syndrome linked to brain tumors [1]. - Omitting NF1, a condition known for an increased risk of gliomas, renders this option incomplete and inaccurate. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 724-725. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1318-1319.

Q: In diffuse axonal injury all are true EXCEPT:

CT scan shows pathognomonic finding. ***CT scan shows pathognomonic finding*** - While CT scans can sometimes show petechial hemorrhages or small white matter lesions in **diffuse axonal injury (DAI)**, these findings are **not pathognomonic** and can be absent even in severe cases. - **MRI** is more sensitive for detecting microhemorrhages and white matter changes, but even MRI findings are not always definitively diagnostic of DAI, especially in milder forms. - CT scan has **low sensitivity** for DAI, often appearing normal or showing only subtle findings. *Usually causes prolonged coma* - **Diffuse axonal injury (DAI)** is a common cause of **prolonged coma** after traumatic brain injury, as widespread shearing forces disrupt neuronal connections [1]. - The severity and duration of coma correlate with the extent of axonal damage, with severe DAI typically resulting in immediate and prolonged loss of consciousness. *Seen in high energy* - DAI typically results from **high-energy acceleration-deceleration forces**, often seen in motor vehicle accidents or falls from significant heights [1]. - These forces cause differential movement between various parts of the brain, leading to **shearing and stretching of axons** [1]. *Form of primary brain injury* - DAI is considered a **primary brain injury** because the axonal damage occurs at the **moment of impact** due to mechanical forces [1]. - This contrasts with secondary brain injuries, which develop over time due to complications like edema or ischemia. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1262-1264.

Q: Which of the following is an intracellular marker or deposition found in Alzheimer's disease?

Tau protein. ***Tau protein*** - **Tau protein** forms **neurofibrillary tangles** within the neurons, which is a hallmark intracellular lesion in Alzheimer's disease [1]. - These tangles disrupt neuronal transport systems, leading to **synaptic dysfunction** and cell death [1]. *A ̢ 40 / 42 (Amyloid-beta 40/42)* - **Amyloid-beta** peptides aggregate to form **extracellular amyloid plaques**, not intracellular deposits, in Alzheimer's disease [2]. - While central to the pathology, these **plaques** are found outside of the neurons in the brain parenchyma [2]. *Alpha-synuclein* - **Alpha-synuclein** is the primary component of **Lewy bodies**, which are intracellular inclusions characteristic of Parkinson's disease and Lewy body dementia. - It is not a primary marker for Alzheimer's disease pathology. *TDP-43* - **TDP-43 (TAR DNA-binding protein 43)** inclusions are characteristic of **frontotemporal lobar degeneration (FTLD)** and amyotrophic lateral sclerosis (ALS). - While sometimes co-occurs with Alzheimer's, it is not a primary or defining intracellular marker for Alzheimer's disease itself. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1292-1294. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1290-1292.

Q: Abnormal accumulation of misfolded protein is seen in?

Creutzfeldt-Jakob disease. ***Creutzfeldt-Jakob disease*** - This is a neurodegenerative disease characterized by the accumulation of **abnormally folded prion proteins (PrPSc)** in the brain, leading to spongiform encephalopathy [1]. - The misfolding of normal cellular prion protein (PrPC) into its infectious and pathogenic form is central to the disease's pathology [2]. *Nephritic syndrome* - This syndrome is characterized by inflammation of the **glomeruli** in the kidneys, leading to hematuria, proteinuria, and hypertension. - It involves immune complex deposition and inflammation, not primarily the accumulation of misfolded proteins. *Sickle cell anemia* - This is a **genetic blood disorder** caused by a mutation in the beta-globin gene, leading to abnormal **hemoglobin S**. - While hemoglobin S can polymerize and deform red blood cells, it is not considered a disease of generalized misfolded protein accumulation in the same sense as prion diseases. *Megaloblastic anemia* - This condition is caused by impaired **DNA synthesis**, often due to **vitamin B12 or folate deficiency**, leading to large, immature red blood cells. - The pathology involves defective cell division and maturation, not the accumulation of misfolded proteins. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1284-1286. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 712-713.

Q: An MRI shows 'eye of the tiger' sign in basal ganglia. Which pathological finding would confirm pantothenate kinase-associated neurodegeneration?

Iron deposits. ***Iron deposits*** - **Pantothenate kinase-associated neurodegeneration (PKAN)** is characterized by abnormal **iron accumulation** in the basal ganglia, particularly the globus pallidus. - The "eye of the tiger" sign on MRI is a classic radiologic feature of PKAN, reflecting specific patterns of iron deposition in the **globus pallidus**. *Neurofibrillary tangles* - **Neurofibrillary tangles** are a hallmark pathological feature of **Alzheimer's disease** and other tauopathies, not PKAN. - They consist of hyperphosphorylated **tau protein** and are found intracellularly within neurons. *Lewy bodies* - **Lewy bodies** are abnormal aggregates of protein, primarily **alpha-synuclein**, found in the brains of individuals with **Parkinson's disease** and **Lewy body dementia**. - They are distinct from the iron accumulation seen in PKAN. *Calcium deposits* - While **calcium deposits** can occur in the brain in various conditions (e.g., Fahr's disease), they are not the primary or defining pathological finding in **PKAN**. - PKAN is specifically linked to dysfunctional **pantothenate kinase** leading to iron accumulation.

Q: An electron microscopy of muscle biopsy shows 'parking lot' appearance. Which additional finding would confirm myotonic dystrophy?

Ring fibers. ***Ring fibers*** - **Ring fibers** are a classic histopathological feature seen in **myotonic dystrophy**, characterized by peripheral myofibrils arranged circularly around a central core [1]. - The "parking lot" appearance on electron microscopy refers to collections of **sarcoplasmic reticulum** and **T-tubules**, which can be seen in various myopathies but are often prominent in myotonic dystrophy, complementing the presence of ring fibers [1]. *Ragged red fibers* - **Ragged red fibers** are characteristic of **mitochondrial myopathies**, indicating abnormal proliferation of mitochondria beneath the sarcolemma. - They are typically identified with **Gomori trichrome stain** and are not a feature of myotonic dystrophy. *Central cores* - **Central cores** are a hallmark of **central core disease**, a congenital myopathy, and are regions within muscle fibers where oxidative enzyme activity is absent. - These are not typically associated with myotonic dystrophy; rather, they suggest a different underlying genetic defect affecting muscle structure. *Nemaline rods* - **Nemaline rods** are rod-like inclusions observed in muscle fibers in **nemaline myopathy**, an inherited disorder often associated with mutations in genes encoding components of the thin filament. - They are distinct from the pathological findings in myotonic dystrophy and point to a specific type of congenital myopathy. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Manifestations Of Central And Peripheral Nervous System Disease, pp. 732-733.

Q: Which tumor arises from embryonic neural cells?

Medulloblastoma. ***Medulloblastoma*** - This tumor arises from **embryonic neural cells** in the **cerebellum**. - It is a highly malignant **brain tumor** most commonly found in children [1]. *Fibrous astrocytoma* - This is a type of **glioma** that arises from **mature astrocytes**, not embryonic neural cells. - It typically occurs in adults and can be found in various locations within the brain. *Neuroglioma* - This is a broad term that refers to **tumors of neuroglial origin**, meaning they arise from glial cells. - It does not specifically refer to a tumor originating from embryonic neural cells. *Ependymoma* - This tumor arises from **ependymal cells**, which line the **ventricles** and **spinal canal**. - While these are technically neural cells, they are more differentiated than the embryonic neural cells that give rise to medulloblastoma. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1314-1315.

Q: Confirmatory diagnosis of rabies on postmortem:

Negri bodies in brain. ***Negri bodies in brain*** - The presence of **Negri bodies** (eosinophilic intracytoplasmic inclusions) found upon histological examination of brain tissue (specifically **Purkinje cells of the cerebellum** and **pyramidal cells of the hippocampus**) is the **pathognomonic microscopic finding** for rabies [1]. - This is considered the **gold standard for postmortem confirmation** because the rabies virus primarily targets and replicates in neuronal tissue, leading to these characteristic inclusions. *Negri bodies in saliva* - While rabies virus can be present in saliva, the presence of **Negri bodies** themselves in saliva is **not a diagnostic criterion**. - **Viral isolation** or **PCR** from saliva might detect the virus, but Negri bodies are cellular inclusions, not free virus particles. *Anti-rabies antibodies in blood* - The presence of **anti-rabies antibodies** in blood typically indicates **prior exposure or vaccination**, not necessarily an active, fatal infection as required for a postmortem diagnosis. - In unvaccinated individuals with clinical rabies, antibodies may only appear in the very late stages, if at all, due to the rapid progression of the disease and the virus's evasion of the immune system in the CNS. *Negri bodies in corneal scrapings* - While rabies virus antigens can sometimes be detected in **corneal impressions or scrapings** during life using **fluorescent antibody tests**, Negri bodies are not typically found or used for diagnosis in these samples [1]. - Corneal testing is primarily a **pre-mortem diagnostic aid** for antigen detection, not for visualizing Negri bodies. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1279-1280.

Q: Diffuse axonal injury is characterized by lesion at:

Junction of gray and white matter. ***Junction of gray and white matter*** - Diffuse axonal injury (DAI) is characteristically located at the **gray-white matter junction** (interface between cortex and subcortical white matter) [1] - The differential density and movement between gray and white matter during **rotational acceleration-deceleration injuries** creates maximum shearing forces at this junction [1] - This is the **classic and most characteristic location** of DAI lesions, particularly in the **parasagittal white matter** of cerebral hemispheres - Other common sites include corpus callosum and dorsolateral brainstem, but the gray-white junction is the hallmark location *White matter* - While DAI does involve damage to white matter tracts and axons, simply stating "white matter" is too non-specific [1] - Many other conditions affect white matter (demyelination, ischemia, etc.) - The **distinguishing feature of DAI** is its predilection for the gray-white interface, not white matter in general *Corpus callosum* - The corpus callosum is indeed a common site for **visible macroscopic DAI lesions** and hemorrhages [1] - However, this is just one specific location rather than the characteristic pattern - DAI is more broadly characterized by lesions at gray-white junctions throughout the brain *Basal ganglia* - The basal ganglia are deep gray matter structures not typically involved in classic DAI - These structures may be affected by other traumatic injuries like **contusions** or **deep hemorrhages** - DAI predominantly affects the interface zones and white matter tracts, not deep gray matter nuclei **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1262-1264.

Question 1

Which of the following genetic syndromes are associated with brain tumours?

1. Neurofibromatosis type 1
2. Neurofibromatosis type 2
3. Tuberous sclerosis
4. Wiskott-Aldrich syndrome

Select the answer using the code given below.

Accepted Answer

1, 2 and 3

Answer

1, 3 and 4

Answer

1 and 2 only

Answer

2, 3 and 4

Question 2

In diffuse axonal injury all are true EXCEPT:

Accepted Answer

CT scan shows pathognomonic finding

Answer

Seen in high energy

Answer

Form of primary brain injury

Answer

Usually causes prolonged coma

Question 3

A child presenting with leukocoria has an intraocular mass. Microscopic examination shows rosettes with scanty cytoplasm and positive synaptophysin. What is the most likely diagnosis?

Accepted Answer

Retinoblastoma

Answer

Medulloblastoma

Answer

Neuroblastoma

Answer

Ependymoma

Question 4

Which of the following is an intracellular marker or deposition found in Alzheimer's disease?

Accepted Answer

Tau protein

Answer

A β 40 / 42 (Amyloid-beta 40/42)

Answer

Alpha-synuclein

Answer

TDP-43

Question 5

Abnormal accumulation of misfolded protein is seen in?

Accepted Answer

Creutzfeldt-Jakob disease

Answer

Nephritic syndrome

Answer

Sickle cell anemia

Answer

Megaloblastic anemia

Question 6

An MRI shows 'eye of the tiger' sign in basal ganglia. Which pathological finding would confirm pantothenate kinase-associated neurodegeneration?

Accepted Answer

Iron deposits

Answer

Neurofibrillary tangles

Answer

Lewy bodies

Answer

Calcium deposits

Question 7

An electron microscopy of muscle biopsy shows 'parking lot' appearance. Which additional finding would confirm myotonic dystrophy?

Accepted Answer

Ring fibers

Answer

Ragged red fibers

Answer

Central cores

Answer

Nemaline rods

Question 8

Which tumor arises from embryonic neural cells?

Accepted Answer

Medulloblastoma

Answer

Fibrous astrocytoma

Answer

Neuroglioma

Answer

Ependymoma

Question 9

Confirmatory diagnosis of rabies on postmortem:

Accepted Answer

Negri bodies in brain

Answer

Negri bodies in saliva

Answer

Anti-rabies antibodies in blood

Answer

Negri bodies in corneal scrapings

Question 10

Diffuse axonal injury is characterized by lesion at:

Accepted Answer

Junction of gray and white matter

Answer

Basal ganglia

Answer

Corpus callosum

Answer

White matter

Neuropathology — MCQs

Neuropathology — MCQs

On this page

Practice by Chapter

Want unlimited practice?