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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_182_библиотеки_им_акад_М_И_Перельмана.pdf
Helminthic Parasitic Infections: Trematodes
OTHER TISSUE TREMATODE INFECTIONS
A bile duct in a liver resection demonstrates an adult
Clonorchis fluke with no inflammation and no
obvious tissue damage. As chronic infection persists, duct
epithelium transforms to carcinomas.
TERMINOLOGY
Manifestations
Clonorchiasis (Chinese or Oriental liver fluke)
Fascioliasis (sheep liver fluke)
Fasciolopsiasis
Opisthorchiasis (Southeast Asian liver fluke or cat liver
fluke)
Paragonimiasis
ETIOLOGY/PATHOGENESIS
Infectious Agents
Clonorchis sinensis
Fasciola hepatica, Fasciola gigantica
Fasciolopsis buski
Opisthorchis felineus and Opisthorchis viverrini
Paragonimus westermani + 8 other species infecting
humans
High magnification of a liver fluke from a liver resection
demonstrates the uterus of this adult female worm, which
contains identifiable Clonorchis eggs .
Hepatomegaly (Fasciola, Opisthorchis, Clonorchis)
Hepatic mass/cholangiocarcinoma (Opisthorchis,
Clonorchis with chronic infection)
Neurological symptoms (Paragonimus)
Laboratory Tests
Examination of body fluids (stool, bronchoalveolar
lavage fluid, or endoscopic biliary collection) for
diagnostic eggs
Serological testing for Fasciola antibodies (due to
resistance to praziquantel)
Treatment
Praziquantel (all species except Fasciola)
Triclabendazole (Fasciola)
Prognosis
Most infections are asymptomatic but may be severe
and life-threatening (Paragonimus)
Wandering developing trematodes may result in
aberrant tissue lesions presenting as masses
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CLINICAL ISSUES
Epidemiology
Worldwide: Fascioliasis (sheep and cattle with
watercress consumption), paragonimiasis (raw or
pickled crustaceans)
Europe/Russia: Opisthorchiasis (raw fish consumption)
Indian subcontinent: Fasciolopsiasis (pigs with
freshwater plant consumption)
Asia: Fasciolopsiasis (pigs with freshwater plant
consumption), clonorchiasis/opisthorchiasis (raw fish
consumption)
Presentation
Hemoptysis, cough (Paragonimus)
Abdominal pain, fever, vomiting, diarrhea, urticaria,
eosinophilia
Ascites, anasarca, intestinal obstruction (Fasciolopsis)
MICROBIOLOGY
Parasite Characteristics
Adult Clonorchis from 10-25 mm, eggs 30 m x 16 m
(very similar to Opisthorchis)
Adult F. hepatica up to 30 mm, F. gigantica up to 75
mm, eggs 140 m x 75 m (very similar to F. buski)
Adult F. buski from 35-75 mm, eggs 140 m x 75 m
(very similar to Fasciola)
Adult Opisthorchis 5-12 mm, eggs 30 m x 12 m (very
similar to Clonorchis)
Adult Paragonimus 8-12 mm, eggs 85 m x 50 m
Life Cycle
All trematodes begin as embryonated eggs in water,
which hatch into miracidia, which infect snails
Inside snails, sporocysts mature to rediae and
then to free-swimming cercariae, which encyst
OTHER TISSUE TREMATODE INFECTIONS
Clinical Issues
Worldwide: Fascioliasis, paragonimiasis
Europe/Russia: Opisthorchiasis
Indian subcontinent: Fasciolopsiasis
Asia: Fasciolopsiasis, clonorchiasis, opisthorchiasis
Treatment: Praziquantel, triclabendazole (Fasciola)
with serologic testing to confirm
Key Facts
Microscopic Pathology
Cross sections in biliary tree with granulomatous
inflammation (especially surrounding eggs)
Lung masses with adult Paragonimus, eggs with
granulomatous response
Top Differential Diagnoses
Ascariasis and other nematode infections
Entamoebiasis, schistosomiasis
Helminthic Parasitic Infections: Trematodes
Cholangiocarcinoma (Clonorchis or Opisthorchis)
into metacercariae on water plants, skin of fish, or
crustaceans
Humans consume undercooked metacercariae, which
then excyst in human digestive tract
Opisthorchis, Clonorchis, and Fasciola reside as adults
in human biliary tree (excreting eggs into stool)
Fasciolopsis resides as adults in small intestine
(excreting eggs into stool)
Paragonimus resides as adults in lung (excreting eggs
into sputum) and, because of its need to migrate,
may infect any organ
Eggs pass into environment and embryonate in water
MICROSCOPIC PATHOLOGY
Histologic Features
Cross sections of trematodes may be found in
biliary tree tissue from resections or at autopsy with
granulomatous inflammation (especially surrounding
eggs)
Cholangiocarcinoma due to chronic inflammation
secondary to Clonorchis or Opisthorchis may contain
worms in dilated ducts/spaces
Lung masses may contain adult Paragonimus with
variable inflammation and eggs with granulomatous
response
Paragonimus found outside of lung will demonstrate
more inflammation and can occur in any organ
DIFFERENTIAL DIAGNOSIS
Ascariasis and Other Nematode Infections
Ascaris worms that wander into biliary tract can die
and cause inflammatory masses; adult nematode
structures and identifiable eggs are usually present
Nematodes that pass through lungs may cause
localized inflammation with eosinophils, but no eggs
will be present (immature stages)
Entamoebiasis
Disseminated Entamoeba histolytica to liver causes
large, necrotic abscess with prominent conspicuous
ameba present
Schistosomiasis
Can involve any organ and produces characteristic
eggs with exuberant granulomatous reaction; adult
worms are inside blood vessels (not lumina)
SELECTED REFERENCES
1. Finsterer J et al: Parasitoses of the human central nervous
system. J Helminthol. 87(3):257-70, 2013
2. Hung NM et al: Global status of fish-borne zoonotic
trematodiasis in humans. Acta Parasitol. 58(3):231-58,
2013
GROSS AND MICROSCOPIC FEATURES
(Left) Liver flukes are flat, somewhat transparent, and tapered anteriorly. They have prominent oral and ventral suckers. (Courtesy J. Doss, MD.)
(Center) A CNS paragonimiasis granuloma is a reaction to eggs that marginate along the thick fibrotic wall and appear as clear, oval spaces
. (From DP: Neuro.) (Right) A cystic structure demonstrates numerous eggs of Paragonimus admixed with calcifications from a lung mass.
(From DP: Thoracic.)
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SECTION 3
Echinococcosis V-3-2
Cysticercosis V-3-6
Helminthic Parasitic Infections: Cestodes
ECHINOCOCCOSIS
V
Protoscolices of Echinococcus are seen from a cyst
(smear). The unique morphology of so-called hydatid
sand is due to the invaginated "head" with hooklets (best
seen with polarized light).
TERMINOLOGY
Synonyms
Hydatid disease
ETIOLOGY/PATHOGENESIS
Environmental Exposure
Contact with feces of carnivorous predators or
association with herbivore hosts
Although geographic distribution is broad, patients
will usually have identifiable primary exposure
Infectious Agents
Echinococcus species cestodes are tapeworms of
carnivorous predators
Incidentally found in humans through contact with
feces of infected animals
4 species (of 6 in the genus) are zoonotic pathogens in
humans
Echinococcus granulosus (cystic)
Definitive host: Canidae (dogs, wolves, foxes,
jackals)
Intermediate host: Herbivores (sheep, goats,
swine, kangaroos)
Echinococcus multilocularis (alveolar)
Definitive host: Canidae and Felidae
Intermediate host: Small rodents
Echinococcus vogeli (polycystic)
Definitive host: Canidae (bush dogs and domestic
dogs)
Intermediate host: Rodents
Echinococcus oligarthrus (unicystic)
Definitive host: Felidae (cats, cheetahs, lions)
Intermediate host: Small rodents
Humans are dead-end hosts and do not transmit
infection
Low-power view shows a cyst in tissue with an outer rim of
fibrosis , a germinal layer (dead) , and debris from
dead daughter cysts .
CLINICAL ISSUES
Presentation
Cystic echinococcosis
Abdominal pain, pleurisy, shortness of breath, bone
pain, "tumor," headaches, or seizures depending on
site and size of cyst
Time course may be prolonged, as primary cyst
grows ~ 1 cm per year until detection or rupture
(between 10 and 20 cm)
Rupture of a cyst (iatrogenically or traumatically)
can lead to immediate anaphylaxis
Any site in the body may be involved, and isolated
reports are numerous
Brain, meninges, spinal cord, vertebral column
Heart, pericardium, lungs, pleura, diaphragm
Liver, spleen, mesentery, abdominal wall
Skin, soft tissue, extremities, bone
Ovary, uterus, kidneys, bladder
Alveolar echinococcosis
Asymptomatic incubation (up to 15 years) with a
slow-growing, fibrotic mass (usually of liver), which
can present with jaundice, right upper quadrant
pain, or hepatic failure
Polycystic echinococcosis
Asymptomatic incubation (~ 10 years) with a slowgrowing, fibrotic mass (liver > lungs > mesentry)
Present with jaundice, right upper quadrant pain,
hepatic failure, shortness of breath, pleurisy, or
abdominal pain, depending on location of cysts
Treatment
Options, risks, complications
Rupture of an intact viable cyst will lead to spilling
of contents and infection of adjacent tissues
Surgical approaches
Intact removal of solitary cyst
Dangerous due to risk of anaphylaxis
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ECHINOCOCCOSIS
Etiology
Echinococcus species are incidentally found in humans
through contact with infected animals
Clinical Issues
Cystic echinococcosis: Abdominal pain, pleurisy,
shortness of breath, bone pain, "tumor," headaches,
or seizures
Alveolar echinococcosis: Asymptomatic slowgrowing, fibrotic mass with jaundice, right upper
quadrant pain, or hepatic failure
Polycystic echinococcosis: Asymptomatic slowgrowing, fibrotic mass (liver > lungs > mesentry)
Imaging Findings
X-ray: Chest or abdomen with solitary or multiple
fluid-filled spaces in involved organs
Key Facts
CT: Daughter cysts within larger cysts or reactive
surrounding inflammation
Microscopic Pathology
Cystic echinococcosis and polycystic echinococcosis:
Thin to thick fibrous response from human host,
a germinal matrix, and daughter cysts contain
protoscolices
Rupture echinococcal disease: Fibrous response with
varying amounts of identifiable necrotic helminth
fragments
Alveolar echinococcosis: Fibrous response with
varying amounts of identifiable daughter cysts
Top Differential Diagnoses
Cysticercosis
Coenurosis
Helminthic Parasitic Infections: Cestodes
Accidental rupture and spillage of contents leads to
recurrence
Drugs
Mebendazole (prolonged duration)
PAIR (percutaneous aspiration, injection of chemicals,
and reaspiration)
Preferred method for diagnosing and treating
solitary cysts of echinococcosis, as it decreases risk of
anaphylaxis and spread of infection
Prognosis
Ruptured cystic echinococcosis may require lifelong
therapy with mebendazole to prevent recurrence of
disease
Spread of cyst contents can create tumor-like
conditions with local spread to other organs
Anaphylaxis can lead to immediate death
IMAGE FINDINGS
Radiographic Findings
Chest or abdomen examination will show solitary or
multiple fluid-filled spaces in involved organs
Ultrasonographic Findings
Multiple echogenic clear to fluid-filled spaces within a
larger cyst of either liver, lung, or abdomen
CT Findings
Higher resolution may reveal structure of daughter
cysts within larger cysts (multiple densities)
Reactive surrounding inflammation (in cases of
rupture)
MICROBIOLOGY
Parasite Characteristics
Cestodes are hermaphrodites (have both male and
female sex organs) but mature proglottids do exchange
spermatozoa through their genital pores within the
definitive host
Cestodes do not have a digestive tract and absorb
nutrients from the environment through their
tegument
Life Cycle
Carnivorous predator (e.g., dog, [definitive host])
excretes proglottids &/or eggs into environment
Herbivores (intermediate host) ingest eggs from plants
or environment
Sheep, goats, cattle, camels, pigs, rodents, humans,
and wild herbivores may be intermediate hosts
Eggs hatch to oncospheres, which penetrate intestinal
wall and migrate to final site of cyst development
Brain, lung, liver, intestine, and bones are all
common sites
Cyst stage is proliferative, grows 1 cm per year, and
produces many protoscolices
When carnivorous predators eat meat of herbivores,
they ingest cysts (does not occur in humans) and
protoscolices
Protoscolices (inverted scolices) evert in gut lumen and
attach to intestinal wall
Viable attached adult tapeworms in digestive tract
produce proglottids and eggs
Culture
There is no role for culture in diagnosis of hydatid
disease
MACROSCOPIC FEATURES
Intact Solitary Cysts (E. granulosus)
Large clear to milky, fluid-filled cysts
Contain smaller white to yellow daughter cysts of
various sizes
Ruptured Cysts or Alveolar Echinococcosis
Large inflammatory to fibrotic masses
Scattered cystic spaces daughter cyst contents
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ECHINOCOCCOSIS
Helminthic Parasitic Infections: Cestodes
V
Polycystic Echinococcosis
Multiple intact cysts (clusters of grapes) adjacent or
scattered through involved organ
MICROSCOPIC PATHOLOGY
Histologic Features
Cystic echinococcosis and polycystic echinococcosis
Intact cysts removed within an organ (e.g.,
lobectomy) demonstrate a thin to thick fibrous
response from human host, a germinal layer, and
daughter cysts that contain protoscolices
Lamellated cyst wall may be the only visible portion
in a resection specimen
Ruptured echinococcal disease
Fibrous response predominates with varying
amounts of identifiable necrotic helminth fragments
Previously ruptured/traumatized cysts may include
acute (neutrophilic) or granulomatous inflammation
Hooklets can be scanned for at low power with
polarized light
Alveolar echinococcosis
Fibrous response predominates with varying
amounts of identifiable daughter cysts
Some cystic spaces may be empty due to the natural
rupture and progression of disease
Because any site in body may be involved, careful
attention must be paid to any "cyst" or "tumor" for
presence of diagnostic hooklets, intact protoscolices,
or cestode material
Cytologic Features
Fine-needle aspiration of solitary cysts (E. granulosus)
should yield diagnostic hydatid sand/protoscolices
Aspiration should only be conducted under medical/
surgical guidance as part of a treatment/removal
procedure due to risk of contamination and spread
Alveolar echinococcosis, due to the natural creation of
daughter cysts with fibrosis in tissue, may not produce
hydatid sand on aspiration
ANCILLARY TESTS
Serologic Testing
Antibodies to echinococcus may be present in hosts
with previous rupture
Cross-reacts with other cestode antigens (e.g., Taenia
species)
Intact, nonruptured cysts may not have elicited an
antibody response
DIFFERENTIAL DIAGNOSIS
Cysticercosis
Taenia solium larvae are small (1-2 cm) and contain a
single protoscolex with hooklets
More likely to have multiple scattered cysts
Coenurosis
Coenurus, or larval bladder, contains multiple scolices
(everted) with hooklets within a single lesion
Caused by Taenia multiceps, Taenia serialis, Taenia
brauni, and Taenia glomerata
Noninfectious Cystic/Polycystic Lesions
Simple cortical cysts, congenital/developmental cysts,
epidermal inclusion cysts, polycystic kidney disease,
cystic primary or metastatic tumors, synovial cysts,
etc.
Diagnostic epithelial structures &/or lack of
echinococcal elements separate on morphologic
criteria
DIAGNOSTIC CHECKLIST
Clinically Relevant Pathologic Features
Pastoral, occupation, or endemic setting exposure
should prompt consideration in abnormal site
"tumors" or unexplained "cysts"
Pathologic Interpretation Pearls
Hooklets are diagnostic of cestode disease but
correlation with history, scolex vs. protoscolex, and
surrounding milieu is required for definitive diagnosis
SELECTED REFERENCES
1. Ahmad M et al: Effect of size on the surgical management
of pulmonary hydatid cyst. J Ayub Med Coll Abbottabad.
26(1):42-5, 2014
2.
Alonso Garca ME et al: Ovarian hydatid disease. Arch
Gynecol Obstet. 289(5):1047-51, 2014
3.
Belhassen-Garca M et al: Study of hydatidosis-attributed
mortality in endemic area. PLoS One. 9(3):e91342, 2014
4. Hemer S et al: Host insulin stimulates Echinococcus
multilocularis insulin signalling pathways and larval
development. BMC Biol. 12:5, 2014
5. Ito A et al: Cystic echinococcoses in Mongolia: molecular
identification, serology and risk factors. PLoS Negl Trop
Dis. 8(6):e2937, 2014
6. Jayant K et al: Spontaneous external fistula: the rarest
presentation of hydatid cyst. BMJ Case Rep. 2014, 2014
7. Kantarci M et al: A rare reason for liver transplantation:
hepatic alveoloar echinococcosis. Transpl Infect Dis.
16(3):450-2, 2014
8. Tuxun T et al: World review of laparoscopic treatment of
liver cystic echinococcosis--914 patients. Int J Infect Dis.
24:43-50, 2014
9. Finsterer J et al: Parasitoses of the human central nervous
system. J Helminthol. 87(3):257-70, 2013
10. Garcea G et al: Surgical management of cystic lesions in
the liver. ANZ J Surg. 83(7-8):516-22, 2013
11. Huang M et al: Primary alveolar echinococcosis
(Echinococcus multilocularis) of the adrenal gland: report
of two cases. Int J Infect Dis. 17(8):e653-5, 2013
12. Kafaji A et al: Spinal manifestation of hydatid disease: a
case series of 36 patients. World Neurosurg. 80(5):620-6,
2013
13. Karaman A et al: Lung metastasis caused by an infection
with Echinococcus alveolaris. Interact Cardiovasc Thorac
Surg. 16(3):411-2, 2013
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Microscopic Features
d
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p
p
Helminthic Parasitic Infections: Cestodes
ECHINOCOCCOSIS
(Left) Alveolar
echinococcosis is a form
of the disease with natural
rupture and generation
of new cysts in tissue,
which leads to dense
scarring . (Right) High
magnification of the
cyst lining in alveolar
echinococcosis shows
the lining germinal layer
and the host chronic
inflammatory response
(due to sequential rupture).
(Left) The germinal layer
and protoscolices
of an echinococcal cyst
within the lung of an affecte
atient demonstrate the
daughter cyst lining
from which the organisms
form. The lamellated wall
, sometimes the only
feature seen in resections,
has bland layers. (Right) An
echinococcal cyst under
olarized light highlights the
refractile hooklets buried
within the protoscolex, a
roperty that is retained in
intact or dead organisms.
(Left) Necrotic debris from
a previously damaged/
dead echinococcal cyst still
contain diagnostic hooklets
in original configuration
and floating within debris
. (Right) Polarized light
will highlight the hooklets
of Echinococcus and make
the search for diagnostic
forms much easier, especially
if morphology is distorted by
dead tissue or inflammation.
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Helminthic Parasitic Infections: Cestodes
CYSTICERCOSIS
V
This section shows a viable Taenia solium cysticercus
with inverted scolex , hooklets , and gastrodermis
. (Courtesy Franz von Lichtenberg Collection of ID
Pathology, BWH.)
TERMINOLOGY
Definitions
Derived from Greek: "Kystic" (bladder) and
"kercos" (tail)
ETIOLOGY/PATHOGENESIS
Infectious Agents
Parasitic tissue infection caused by larval cysts
(cysticerci) of tapeworm Taenia solium
Cysticercus (metacestode stage): Milky white,
fluid-filled cyst (1-2 cm in diameter) with single
invaginated protoscolex
Transmitted by ingestion of eggs found in feces of
person with intestinal tapeworm
Oncospheres hatch in intestine, invade intestinal wall,
and migrate to muscles, brain, and liver, then develop
into cysticerci
Symptoms occur months to years after infection,
typically when cysts start to die, releasing parasite
antigens with acute inflammatory response
CLINICAL ISSUES
Epidemiology
Tapeworm infection (taeniasis) and cysticercosis occur
globally
Highest rates of infection in areas of Latin America,
Asia, and Africa with poor sanitation and free-ranging
pigs that have access to human feces
Seizure disorder in 2.5 million people worldwide;
estimated 50,000 fatal cases per year
Site
Brain, muscle, spine, eyes, skin, heart
MR of a patient with neurocysticercosis shows peripheral
enhancement of the cyst wall with a central "dot"
representing the scolex. (From DI2: Brain.)
Presentation
Symptoms dependent on location, size, number, and
stage of cysts (viable, degenerating, or calcified)
Neurocysticercosis (NCC): Usually presents with
seizures (70-90%) or headaches
Confusion, difficulties with balance, and
hydrocephalus may occur; may be asymptomatic
Muscle infection: Typically asymptomatic; may
present with tender or nontender lumps
Eye infection: Rarely cause blurry or disturbed vision
Laboratory Tests
CSF: Lymphocytic or eosinophilic pleocytosis, low
glucose, high protein
EEG: Abnormal in 50% of cases; no specific pattern
Enzyme-linked immunoelectrotransfer blot (EITB):
Serum or CSF
100% specific; 90% sensitive for > 2 lesions
50-60% sensitive for single or calcified lesions
ELISA, RT-PCR, Western blot (CSF)
Treatment
Primary prevention
Identification and treatment of tapeworm carriers
Avoidance of food/water that might be
contaminated by human feces
Management of neurological complications
Conventional anticonvulsants for
neurocysticercosis-associated seizure disorders
Corticosteroids (e.g., dexamethasone) to suppress
inflammatory response
Neurosurgical intervention: Endoscopic removal
of intraventricular cysts; placement of ventricular
shunts
Antihelminthic treatment
Oral albendazole and praziquantel available in USA
Indicated for symptomatic patients with multiple,
live (noncalcified) cysticerci
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CYSTICERCOSIS
Etiology
Parasitic tissue infection; inflammatory response to
dying larval cysts of Taenia solium
Clinical Issues
Seizure disorder in 2.5 million people worldwide;
50,000 fatal cases/year
Symptoms dependent on location, size, number, and
stage of cysts (viable, degenerating, or calcified)
Enzyme-linked immunoelectrotransfer blot (EITB)
detects serum or CSF antibodies
Treat with anticonvulsants, corticosteroids,
surgery, &/or antihelminthic drugs (albendazole,
praziquantel)
Relatively good prognosis for neurocysticercosis with
few parenchymal cysts
Administered with caution due to inflammatory
response induced by larval death; coadministration
with corticosteroids
Key Facts
Macroscopic Pathology
Cysts intraparenchymal, in cortical sulci, or
subarachnoid
Translucent cysts with 2-3 mm scoleces (vesicular
phase); involuting with opaque fluid (colloidal
phase); small calcified nodules (calcified stage)
Microscopic Pathology
Vesicular cyst wall: Outer cuticular, middle
pseudoepithelial cellular, and inner reticular layers
Viable larvae: Scoleces with rostellum, hooklets, and
suckers
Later stages of degeneration: Absence of larvae,
fibrotic capsular abscess-like walls, variable chronic
inflammation
Remote infection with dystrophic calcified nodules
opaque fluid in colloidal phase, and degenerating cysts
as small calcified nodules in calcified stage
Helminthic Parasitic Infections: Cestodes
Prognosis
Neurocysticercosis with parenchymal disease of
a small number of cysts has a better prognosis
than parenchymal disease with > 50 cysts or with
extraparenchymal cysts
IMAGE FINDINGS
MR Findings
More sensitive than CT at showing cysts in some
locations (cerebral convexity, ventricular ependyma)
and for demonstrating surrounding edema and
internal changes indicating cysticerci death
CT Findings
Superior to MR for demonstrating small calcifications
MICROBIOLOGY
General Features
Adult tapeworm: Up to 1,000 proglottids and 9 m in
length; armed rostellum scolex with double row of
hooklets and 4 cup-like suckers
Gravid proglottids: Nearly 2x as long as broad; uterus
with 7-13 lateral branches per site
Eggs: Thick, radially striated sheet (31-43 m in
diameter)
MACROSCOPIC FEATURES
General Features
Cysts intraparenchymal, in cortical sulci, or
subarachnoid with grossly normal surrounding brain
Translucent viable cysts with discrete 2-3 mm scoleces
in vesicular phase, involuting/degenerating cysts with
MICROSCOPIC PATHOLOGY
Histologic Features
Vesicular cyst wall: Outer cuticular layer, middle
pseudoepithelial cellular layer, inner reticular layer
Viable larvae contain scoleces with rostellum,
hooklets, and suckers
Later stages of degeneration characterized by absence
of larvae, with fibrotic capsular abscess-like walls, and
variable chronic inflammation (lymphocytes, plasma
cells, and eosinophils)
Remote infection with dystrophic calcified nodules
DIFFERENTIAL DIAGNOSIS
Coenurosis
Metacestode larvae (Taenia multiceps and Taenia
serialis)
Similar morphologic features to cysticerci;
distinguished by presence of multiple scoleces
Other Intraventricular Cysts
Choroid plexus cysts, ependymal cysts, colloid cyst
Cyst wall lined by cuboidal to columnar epithelium;
no organism parts
SELECTED REFERENCES
1. Del Brutto OH: Neurocysticercosis. Handb Clin Neurol.
121:1445-59, 2014
2. Baird RA et al: Evidence-based guideline: treatment of
parenchymal neurocysticercosis: report of the Guideline
Development Subcommittee of the American Academy of
Neurology. Neurology. 80(15):1424-9, 2013
3. Mewara A et al: Neurocysticercosis: A disease of neglect.
Trop Parasitol. 3(2):106-13, 2013
4. Lichtenberg F: Pathology of Infectious Diseases. New York:
Raven Press, 1991
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