Pathology Flashcards
What process do they arrows likely represent after a stroke?
Wallerian degeneration of cortical spinal fibers.
What are the small oval cells? What is the common stain for them?
Astrocytes: small, no cytoplasm
GFAP
What are the small cells on the very outer layer? They form the arachnoid membrane.
What do they stain with?
Meningothelial cells
Stains positive for epthelial membrane antigen (EMA)
What type of cells are these? What do they produce? What do they stain with?
Choroid Plexus: Large cuboidal epithelium overlying blood vessels, connective tissue and meningothelial cells.
- Produces CSF
- Stains positive for transthyretin
What cell type is circled?
Alive or dead?
When do they appear after ischemia?
Neurons become brightly eosinophilic with loss of the Nisl substance within 6-24 hours of ischemia (“Red neurons”).
What are these cells? What would they stain + for?
When do they appear after ischemia?
Reactive astrocytes. GFAP, as always :)
12-36 hours
What are these cells? When do they invade after a stroke?
Polymorphonuclear cells invade the ischemic territory within hours and peak at 48-72 hours.
When does vascular proliferation occur after a stroke?
What imaging correlate does it have?
After 48 hrs. Should allow for some contrast enhancement due to BBB breakdown.
What is caused the area in the circle? What is the finding the arrow is pointing to?
Cystic cavity surrounded by gliotic tissue with glial strands (circle)
– There is compensatory (ex-vacuo) ventricular enlargement
What type of stroke caused this? What is the underlying vascular problem identified on pathology?
Lacunar infarction
• Infarctions ranging in size from 1 mm to 1.5 cm (arrow)
• Classically, the walls of small arteries become thickened from the formation of hyalinemembranes (lipohyalinosis) (circle)
– Caused by chronic hypertension
- These arteries may also rupture and cause hemorrhage
Old guy found down and brought back to life. Died of inability to feed himself. What was the cause?
Watershed infarction. Couldn’t eat due to man in a barrel like weakness and couldn’t get food to his mouth. So sad.
What cells are killed of by transient global hypoperfusion?
Transient shock or cardiopulmonary arrest causes focal ischemic injury to neurons with high metabolic rates:
– Layer 3 and 5 of cortex
– Hippocampus
– Purkinje cells
What is this pathology? What is the black stain?
Tearing of the endothelial lining of the blood vessel with extravasation of blood
into the vessel wall
Seen in:
– Marfan’s syndrome
– Fibromuscular dysplasia,
– Ehlers-Danlos type IV
– Trauma
I believe that is reticulin staining.
What is this process? How can you differentiate it from viral encephalitis?
Vasculitis
• May be part of a systemic vasculitis or isolated to the CNS.
• Requires transmural vessel wall inflammation
17 year old out parting at Elich’s and then got gastro and is overweight on OCPs. Presents with seizure then rapid decline.
Wa happened?
Venous Sinus Thrombosis
• Venous congestion over the convexities with parietal petechial hemorrhages.
Associated with:
– Post-partum
– Dehydration
– Hypercoagulable states
– Adjacent inflammation
(e.g., mastoiditis).
15 year old presents with first seizure. What is the cause of this pathology? Is there normal tissue?
AVM
Located in cortex
Composed of both large arteries (open arrow) and veins (solid arrow) without
intervening capillaries.
Between vessels there is gliotic nonfunctional hemosiderin stained tissue (circle).
10 year old shows up after seizure and has an MRI with popcorn lesions.
Cavernous Malformation
Located in cortex or less frequently in the brainstem.
• Composed of thinwalled vessels (arrow).
• There is no intervening parenchyma between the vessels (circle).
Name the common vascular malformations, if they have arterial flow, what the vessels in the malformation are, if there is a draining vein, and if the intermixed brain tissue is normal.
What are the most common locations for hypertensive hemorrhages in order of frequency?
Hypertensive Hemorrhage
• Commonly occur in the:
– Putamen (65%)
– Pons (10%)
– Cerebellum (10%)
– Thalamus
• These are the same locations of lacunar infarctions.
What study should be ordered on a patient with a similar presentation (before autopsy)?
Angiography.
Subarachnoid Hemorrhage
• Caused by aneurysmal rupture ortrauma
• Overlying the blood is the arachnoid membrane (arrow).
What was the mechanism of injury for this patient?
Area of hemorrhagic necrosis from cerebral contusion.
– Usually affects the crest of gyri.
– Frequently seen in subfrontal and anterior temporal lobes as the base of the brain slides over the irregular skull base
• Blood is removed by macrophages leaving an irregular tan discoloration.
What is the mechanism of the injury seen here?
Diffuse Axonal Injury
• Widespread ruptured axons from trauma.
– Neuroimaging is normal but patients are comatose, may see microhemorrhages in white matter tracts.
- On gross examination, there is white matter atrophy.
- The injured axons dilate (“axon retraction balls”)
Name the herniation and vessel at risk.
Subfalcine: an edematous cingulate gyrus (arrow) compresses the ipsilateral anterior
cerebral artery as it runs in the falx cerebri.
Name the herniation and vessel at risk
Uncal Herniation
• The medial temporal lobe (uncus) herniates across the tentorium cerebelli compressing:
– the ipsilateral 3rd nerve
– the midbrain resulting in compression of the contralateral cerebral peduncle on Kernohan’s notch
– the posterior cerebral arteries resulting in occipital lobe infarcts.
What went for a dip?
What is the brainstemp pathology?
Tonsillar Herniation
• With elevated posterior fossa pressure, the cerebellar tonsils are forced downward into the foramen magnum causing hemorrhage and compression of the medulla.
• Since the blood vessels are fixed by the dura, downward displacement of the brainstem causes rupture of the penetrating arteries resulting in multiple linear hemorrhages (Duret).
Patient presents with fever, neck stiffness and somnolence. Dies two days later. What is causing the appearance of the patholigic specimen?
Bacterial Meningitis
– Purulent material in the subarachnoid space (arrow) from abundant polymorphonuclear cells.
What is the process depicted both on gross and microscopic section? What are common causes of these findings?
Granulomas
• Composed of epitheliod macrophages (closed arrow), multinucleate giant cells (circle), lymphocytes (open arrow)
• Caused by:
– Tuberculosis
– Fungi
– Spirochetes
– Sarcoidosis (noncaseating)
– Foreign body
Patient recently moved from out of country or has AIDs and a wicked cough. Now dead. Presented with chronic headache and altered mental status.
What is the cause?
Tuberculosis Meningitis
• Subacute to chronic course
• Tuberculosis, fungus, and spirochetes have a predilection for the base of the brain.
• Tuberculosis and other mycobacterium are acidfast bacteria (arrow).
Patient is from the southwest and had a bad cough. Now subacute meningitis.
Coccidiodidomycosis
– small yeast
– large spherical endospore (arrow).
Which yeast is it?
Aspergillus
– narrow regular hyphae branching at acute angles (arrow) invading blood vessels.
• Mucormycosis (bottom)
– broad irregular hyphae branching at 90º (circle).
• Both are angioinvasive
Immunecompromised patient with this is a pathologic sample. Name the yeast.
Candidiasis
• Rare CNS pathogen
• This fungi exists as a yeast.
• Multiple yeast may connect to each other mimicking branching hyphae (pseudohypae) (circle).
Patient with HIV presents with multiple ring enchanceing lesions. Unfortunately, dies. What is the cause of ring enchanging lesions?
Toxoplasmosis
• Exists in 2 forms
– Slow-growing round bradyzoite (circle)
– Active-growing comma-shaped tachzoites
• Also see chronic inflammation (lymphocytes and plasma cells)
Patient with seizures and CSF pleocytosis. Biopsy obtained in work up ( I make the clinical scenario up by the way). Please diagnose now with this limited information. Why is it not vasculitis?
Viral encephalitis
• Microglial nodules
– hypercellular cluster containing microglia and reactive astrocytes (circle).
• Perivascular cuffing
– Lymphocytes surrounding blood vessel (arrow).
– Similar findings in demyelinating disease and CNS lymphoma
These are 2 different types of inclusion bodies. What viral processes are they most typical for in each case?
Cowdry A
– Single, large inclusion surrounded by a halo that efface the nucleus (circle).
– Seen in HSV, CMV, VZV, and SSPE.
Cowdry B
– Multiple, small inclusions without a halo that do not efface the nucleus (arrows).
– Seen in Polio or normally in the substantia nigra (Marinesco body), but also in normal aging.
Patient presents with fever, headache, AMS and seizures.
For extra points (Adam will by you dinner, he promised): If the patient survives, but then starts acting like Gary Busey what disorder do they have, what structures are involved. What are the main clinical findings?
HSV Encephalitis
• HSV has a predilection for the temporal lobes/ basal forebrain (circle).
• Classically presents as a hemorrhagic encephalitis
Kluver-bucy syndrome (bilateral lesions of mesial temporal lobes & Amygdala)=
“HIP HIP”
H = Hypermetamorphosis (old visual stimuli approached as if they are new)
I = Increased oral exploratory behavior
P = Placidity (Docility- dimished fear)
H = Hypersexuality + Hyperphagia
I = Impaired memory (Anterograde Amnesia)
P = Psychic Blindness (objects in visual field treated inappropriately)
Patient is bit by a bat and is now afaid of water. What are the inclusions?
Rabies
• Characterized by eosinophilic intracytoplasmic inclusions within pyramidal cell neurons (Negri bodies) (circles).
• Carried by:
– Raccoons
– Skunks
– Bats
– Foxes
– Coyotes
Patient with MS, presents with headache, difficulty with math, oh and is on Tysabri, once got rituximab, too.
Would you A) do plasmapheresis B) give more tysabri C) do nothing?
Progressive Multifocal Leukoencephalopathy (PML)
• Necrotic demyelination beginning in the white matter within a cortical gyrus (circle).
• Characterized by:
– Ground glass inclusions in oligodendroglia nuclei (blue arrow)
– Bizzarre astrocytes (black arrow)
Please, plasmapheresis.
Old guy with memory problems. What are they inclusions? What is the protein involved?
Neurofibrillary tangles
– intracytoplasmic neuronal aggregates of tau protein that take the shape of the neuron’s cell body. In pyramidal cells, they appear flame shaped (arrow).
Same old guy with memory problems. What is this patholgical finding? What is the protein involved?
Neuritic plaques (circle)
– extracellular accumulation of an amyloid core surrounded by swollen neuritic
processes (look like burntout camp fires).
In Alzheimer’s both of these can be found. What are they?
• Granulovacuolar degeneration (top and bottom)
– Small cytoplasmic vacuoles that contain a single granule (circles)
• Hirano bodies
– Rod-shaped eosinophilic inclusions that appear adjacent to neurons in the neuropil (arrow).
50 year old, previously did not have a sweet tooth. Now also disinhibited.
What is the disease? What chromosome has it been associated with?
Frontotemporal Dementia
• Severe focal atrophy of the frontal and temporal lobe
• with sparing of the posterior 2/3 of the superior temporal gyrus (knife-edge)
Chromosome 17
In FTD some with have these inclusions. What are they made out of?
• Pick bodies
– Intracytoplasmic neuronal oval aggregates (circle) of tau (arrow).
• May also see
– neuronal loss with gliosis
– ballooned neurons with achromatic cytoplasmic inclusions
Patient presents with rigidity, falls and limited up gaze. Pathology obtained.
Do they have retrocollis or anterocollis?
Progressive Supranuclear Palsy (PSP)
• Intracytoplasmic neuronal aggregates of tau throughout the brainstem
– These aggregates take the shape of the neuron’s cell body appearing globose” (arrow).
PSP- retrocollis
MSA- anterocollis
What area of the brain is this? What does it project to? What disease is this most likely?
Midbrain (Substantia Nigra Pars Compacta). Caudate. Parkinson’s disease.
There is loss of pigmentation of the substantia nigra (arrows) and locus ceruleus.
What type of Body is this? What is the protein associated with it?
Lewy Body
The pigmented neurons contain an eosinophillic cytoplasmic sphere with a clear halo inclusions. (circle).
Composed of multiple intracellular neuronal proteins
– Identified by staining for alpha-synuclein (arrow).
• May be present in non-pigmented neurons such as hippocampus (circle) or cortex in diffuse Lewy body dementia (DLBD)
Patient with autonomic symtpoms, bradykinesia and hot crossed bun sign. What is the inclusion, what cell type is it in?
Multiple System Atrophy (MSA)
• There are intracytoplasmic inclusions in oligodendroglia that stain positive for alpha-synuclein (arrow).
Plus it may now be a prion disease. Don’t eat brains with MSA.
Disease, gene, repeat, chromosome?
Huntington’s disease
• Gross brain atrophy with ex-vacuo ventricular dilation
• Focal atrophy of the caudate
• Neuronal loss and gliosis of the caudate and putamen, particularly the medium spiny neurons.
Gene: HTT
Chromosome: 4
Repeat: CAG
Disease and pathology, please?
Creutzfeldt-Jakob Disease (CJD)
• Severe cortical atrophy with cystic changes
• Spongiform changes in neuropil with neuronal loss and gliosis.
Patient with CJD, what type?
New variant CJD
• Characterized by a ring of spongiosis surrounding a central prion protein amyloid core (“florid plaque”) (circle).
I hope this stuff it not on the test.
Patient with elevated liver enzymes, movement disorder and a bit wacky. What is accumulating in the putamen? What type of cells are circled?
Wilson’s disease
• Atrophy and copper accumulation in the putamen (arrows)
• Alzheimer type 2 astrocytes
– swollen irregular nuclei with peripheral displacement of the chromatin resulting in central clearing (circles).
– cytoplasm is not prominent
– Seen in all hyperammonemic states
Two different processes affecting the Globus Pallidus. One in a kid with developmental delay and iron accumulation. The second an adult who was found down on the first cold day of winter.
Diseases of the Globus Pallidus
- Neurodegeneration with Brain Iron Accumulation Type I (PantothenakeKinase 2 deficiency)
– Iron deposition in the globus pallidus with resulting tan discoloration (arrows)
• Carbon Monoxide
– bilateral liquefactive necrosis of the globus pallidus (circles).
Name the alcohol for each image causing teh damage.
Toxicity from alcohols
• Methanol causes
– hemorrhagic necrosis of the putamen. Retinal ganglion cell degeneration.
– Severe edema and white matter hemorrhage.
• Ethanol causes
– Atrophy of the anterior superior vermis
– Necrosis of corpus callosum (Marchiafava- Bignami)
Patients presenting with the disorder depicted will have hemorrhage in what 4 areas?
Wernicke’s Encephalopathy
• Characterized by hemorrhage into
– mammillary bodies
– hypothalamus
– periaqueductal gray
– dorsal medial nuc. of thalamus
• Central Chromatolysis (bottom)
– The center of the neuron is homogenously eosinophilic with peripheral displacement of the nucleus and Nisl substance (circle).
Two disorders are depicted due to metabolic causes of demyelination.
Describe please
Metabolic diseases resulting in demyelination
• Central Pontine Myelinolysis
– symmetric central pontine demyelination
– May also affect the corpus callosum (extra-pontine)
• Subacute combined degeneration (B12 deficiency)
– Secondary demyelination of the dorsal columns and lateral corticospinal tracts (arrows).
– also causes optic neuropathy, peripheral neuropathy, and cortical dysfunction
What is the likely disorder causign demyelination here? Circle clearly needed.
Multiple Sclerosis (MS) • Spinal cord demyelination is asymmetric and does not respect vascular territories or individual tracts (circle).
What are the three main leukodystrophies that spare the subcortical U-fibers?
What genes are involved? Inheritance?
Leukodystrophies that spare the subcortical U-fibers
• Metachromatic Leukodystrophy (top) Arylsulfatase A (Autosomal recessive)
– White matter stains brown with cresyl violet instead of violet (arrow).
• Adrenoleukodsytrophy ABCD1 (x-linked) leads to build up of VLCFA
– Asymmetric with posterior predominance
• Krabbe’s disease GALC- galactocerebroside β-galactosidase, (autosomal recessive)
– large multinucleate histiocytes (globoid cells) (circle). Accumulation of lipids
What are 2 leukodystrophies that involve the U-fibers?
Gene?
Inheritance?
Leukodystrophies that involve the subcortical U-fibers
• Canavan’s disease -ASPA (autosomal recessive) Leads to NAA accumulation
– spongiform changes in the white matter (circle).
• Alexander’s disease GFAP (Autosomal Dominant)
– Characterized by intracytoplasmic astrocyte eosinophilic corkscrew inclusions (Rosenthal fibers) (arrow).
– Rosenthal fibers are also seen in pilocytic astrocytomas.
What is this congenital malformation?
Holoprosencephhaly
• Failure of cleavage of the prosencephalon
• Single cortical sphere with a single ventricle.
• Midline structure (olfactory nerves and corpus callosum) are absent.
• Associated with severe abnormalities of facial development
– single eye
– probiscus
Identify the missing structure.
Agenesis of the Corpus Callosum (arrow)
• Develops from anterior to posterior
– Partial agenesis (absent splenium)
• Results in inappropriate formation of the cingulate gyrus with radial sulci instead of longitudinal sulci (circle).
Where is the origin of the hemorrhage?
Germinal matrix hemorrhage
• All cortical cells (neurons and glia) arise from pluripotent cells along the ventricle (germinal matrix).
• The germinal matrix has a fragile blood supply and hemorrhage is common in premature babies (arrows).
What are the common genes known to be associated with this brain malformation? What is their mode of inheritance?
Lissencephaly (“smooth brain”)
– Diffuse failure to populate the cerebral cortex with neurons resulting in absent sulci and gyri.
Lis 1 - Miller-Dieker syndrome with facial changes consist of high and prominent forehead, bitemporal hollowing, short nose with upturned nares, protuberant upper lip with downturned vermillion border, and small jaw (autosomal dominant). Can also cause posterior predominant subcortical band heterotopia.
DCX- X-linked with boys having lissencephaly. Girls typically with have subcortical band heterotopia.
What is this defect? What type of disorder is it thought to be: migrational, proliferation, organization?
Schizencephaly (“spilt brain”) – Organizational defect.
– Focal failure to populate an area of cortex with neurons
– The resulting cavity is bordered by gray matter
Some texts still refer to this as a genetic defect though the recent Barkovich classification reports that the majority are vascular in nature.
http://brain.oxfordjournals.org/content/brain/early/2012/03/16/brain.aws019.full.pdf
What are the defects demonstrated below?
Destruction of normally formed cortex
• Hydranencephaly
– diffuse destruction of cortex by infection or a vascular process
• Porencephaly– focal destruction of cortex.
– The resulting cyst is lined by glial sheets and meninges.
What is the defect noted here?
Congenital Aqueductal Stenosis
• Non-communicating hydrocephalus with dilation of the lateral
ventricles (arrow) and third ventricle (circle).
• Neonates present with increasing head circumference.
Hydrocephalus is probably the correct answer without an MRI or slice of brainshow blood or loss of aqueduct.
Name the tumor and type of rosette demonstrated.
Medulloblastoma
• Most common childhood brain tumor (25%).
• Usually located in the midline vermis with necrosis (arrow).
• Sheets of monotonous small blue cells
– Arranged in a circle with the center filled with cytoplasmic processes (Homer Wright rosettes)
Name the tumor and type of rosette.
Retinoblastoma
• Located in the retina
• Sheets of monotonous small blue cells
– Arranged in a circle forming a true lumen (Flexner-Wintersteiner rosettes)
Name the tumor and identify eosinophilic corkscrew like inclusions.
Pilocytic Astrocytoma
• Circumscribed cystic lesion with a mural nodule
– Predilection for posterior fossa
– also frequently occur in hypothalamus, brainstem and optic nerve
– 20% of childhood tumors
• Spindled astrocytes (stain with GFAP) with intracytoplasmic eosinophilic corkscrew inclusions (Rosenthal fibers)
Name the tumor. Staining is GFAP.
Low grade astrocytoma
• Diffuse astrocytoma involving the thalamus
• There is increased cellularity of astrocytes, which stain for GFAP
– Necrosis and vascular proliferation are absent.
Name the tumor and findings characteristic of tumor type/grade.
Glioblastoma Multiforme (GBM) WHO Grade IV
• Classic butterfly lesion of GBM crossing the corpus callosum
– Lymphoma also involves the corpus callosum.
• May arise de novo or progress from a lower grade astrocytoma.
Most GBM are primary though some may arise from lower grade. Common genetic progression is loss of p53 and then LOH of 10q. Also associated with p16 deletion, PTEN mutation, EGFR amplification. IDH1 also associated.
Findings in Grade IV
1)Pseudopalisading necrosis
– areas of ischemia and necrosis occur as the tumor outgrows its blood supply.
2)Endovascular proliferation
– Immature thickened capillaries develop secondary to angiogenic factors produced by the tumor
Patient with HIV and new CNS lesions. Name the disease. Name the associated virus.
Primary CNS Lymphoma
• Seen in immunocompromised states (e.g. AIDS- EBV association)
• B-cell lymphoma (85%)
• B-cells surrounding blood vessels (perivascular cuffing) (circle).
• The lymphoma cells have nuclear pleomorphism (arrows).
Name the tumor and genetic change associated with good response to chemotherapy.
Oligodendroglioma
• Uniform small round dark nuclei surrounded by a perinuclear halo (fixation artifact) (“fried egg”) (circle).
• Delicately branching vessels (chicken wire) (arrow).
• Loss of heterozygosity for 1p and 19q is a favorable prognostic factor to respond to chemotherapy.
Name the tumor and the type or rosette. Name an associated genetic disorder and chromosome.
Ependymoma
• Located in the 4th ventricle (without necrosis) (arrow).
– Also occur in the filum terminale
• Perivascular psuedorosettes
– ependymal cells that stain positive for vimentin surround a blood vessel (common)
• Ependymal rosettes (circle)
– ependymal cells arranged in a circle forming a true lumen (uncommon)
NF2- chromosome 22
Name the tumor
Paraganglioglioma
• Commonly located in the filum terminale
• Glandular appearance that mimics an ependymoma
• Stains positive for synaptophysin (a neuronal marker)
Name the tumors and typical location
Tumors of the Choroid Plexus
• Located within the ventricle
• Papilloma (circle)
– Hypercellular with normal choroid plexus architecture.
– Stains positive with transthyretin.
• Carcinoma (arrow)
– Childhood tumor
– Loss of normal architecture and staining
Patient with bilateral temporal hemianopsia. Lets play name the tumor. (I recommend calling a pathologist. They are paid much better to do this.)
Pituitary Adenoma
• Hypercellularity
• Single cell type
• Destruction of the fibrovascular septa with resulting loss of the acinar structure (circle).
Name this tumor. Note it is deidentified, though may belong to a wolverine.
Adamantinous Craniopharyngioma
• Solid and cystic components
– A viscous dark brown fluid fills the cyst
• Islands of peripheral columnar pallisading epithelial cells embedded in a collagenous matrix (arrow).
• Nodules of plump pale keratin (circle).
Adamantinomatous
This type is seen predominantly in children. It consists of reticular epithelial cells which have appearances reminiscent of the enamel pulp of developing teeth.
There may be single or multiple cysts filled with thick oily fluid high in protein, blood products, and/or cholesterol, creating the so called “machinery oil”. “Wet keratin nodules” are a characteristic histological feature. Calcification is usually present: ~90
Papillary
The papillary subtype is seen almost exclusively in adults and is formed of masses of metaplastic squamous cells. “Wet keratin” is absent. Cysts do form, but these are less of a feature, and the tumour is more solid. Calcification is uncommon or even rare.
Name the pineal tumor
Pineal Germinoma
• Most common tumor of the pineal gland
• Two cell populations
– small dark reactive lymphocytes
– large atypical cells with prominent nucleoli.
• Stains positive for placental alkaline phosphatase
What am I?
Meningioma
• Arise from meningothelial cells of the arachnoid.
• Located
– Over the convexities
– At the skull base
– interventricular
• Sheets of nuclei with indistinct cell borders with
– menigothelial whorls
– psammoma bodies
• Stain with epithelial membrane antigen
What tumor am I? What are the Antoni areas? What is a vercoray body?
Schwannoma
• Arise from Schwann cells of any peripheral nerve
• Adjacent low cellular areas (Antoni B) and densely cellular areas (Antoni A)
• The nuclei may appear pallisading (Vercoray
body)
What neuromuscular disorder is this likely to be? What tracts are demyelinated?
Amyotrophic lateral sclerosis (ALS)
• Axonal loss of the upper and lower motor neurons
• The ventral motor roots are atrophied
• There is secondary demyelination of the lateral cortical spinal tracts
What pathology is this on a slide of peripheral nerve?
“onion bulbing” due to
chronic demyelination and
remyelination (circle).
Patient and parent have a history of peripheral neuropathies that resolve. name the pathological finding and gene.
Hereditary neuropathy with liability to pressure palsies (HNPP)
– sausage-shaped focal swellings in the myelin sheath called tomaculae (arrow).
Loss of PMP22
Name the type of myopathy and the microscopic pathological findings demonstrated here.
Neuropathic muscle biopsy
• Target fibers
– central clearing surrounded by dark ring surrounded by another pale zone
• Fiber type grouping.
– Clustering of type 1 or type 2 fibers
• Group atrophy
– Atrophy of a fascicle with both type 1 and type 2 fibers
Which one is dermatomyositis and which one is polymyositis?
Inflammatory myopathies
• Polymyositis
– Inflammation between muscle fibers (endomysial) with muscle fiber destruction (circle).
• Dermatomyositis
– Atrophy of muscle fibers around a fascicle (perifascicular) secondary to capillary inflammation (arrow).
Name the myositis
Inclusion body myositis
• Characterized by serpentine vacuoles studded by amyloid protein inclusions (rimmed vacuoles) (circle).
• May also see mild endomysial inflammation
What is the cause of this type of myopathy?
Mitochondrial myopathy
– subsarcolemmal accumulations of eosinophilic mitochondria (“ragged red fibers”) (circle).
What is the indication for steroids in this disorder?
Muscular dystrophy
– degenerating fibers/ regenerating fibers (necessary)
– fiber rounding, central nuclei, variation in fiber size (nonspecific)
– Increased connective tissue (arrow).
Steroids for DMD to increase time patients are ambulatory.
Name the congenital myopathy
Nemaline Rod
– Purple aggregates of muscle filament originating from the Zlines
Name the congenital myopathy and related gene.
Central Core
– Central clearing that runs the entire length of the muscle fiber- Different than that seen in neuropathic myopathy with target.
Gene is RYR1 and is inherited in AD fashion. Risk for malignant hyperthermia with anesthesia.
what is depicted
amyloid deposition around a muscle
what disorder is depicted?
hyalin body myopathy
what type of disorder is depicted?
statin myopathy- muscle fiber necrosis with phagocytosis.
what tumor is depicted?
pilocytic astrocytoma- dense fascles intermixed with loose microcystic areas.
what tumor is depicted?
pilocytic astrocytoma- dense area with rosenthal fibers.
what type of tumor is depicted?
meningioma- psammoma body
what type of infection? in what type of cells are the inclusions?
CMV, microglia
what disease of the spinal cord is depicted?
HIV vacuolar myelopathy- spongy degeneration of posteror and lateral columns
what is depicted?
lewy body
what disorder is depicted?
infantile SMA- pan fascicular myopathy
what tumor?
craniopharyngioma
what tumor
pituitary adenoma
