Lam et al. Journal of Medical Case Reports (2016) 10:144
DOI 10.1186/s13256-016-0910-y

CASE REPORT

Open Access

Pulmonary neuroendocrine carcinoma
mimicking neurocysticercosis: a case report
John C. Lam1*, Stephen R. Robinson1, Andrew Schell2 and Stephen Vaughan1,3,4

Abstract
Background: Neurocysticercosis occurs when the eggs of the pork tapeworm (Taenia solium) migrate and hatch
into larvae within the central nervous system. Neurocysticercosis is the most common cause of seizures in the
developing world and is characterized on brain imaging by cysts in different stages of evolution. In Canada,
cases of neurocysticercosis are rare and most of these patients acquire the disease outside of Canada. We report
the case of a patient with multiple intracranial lesions whose history and diagnostic imaging were consistent
with neurocysticercosis. Pathological investigations ultimately demonstrated that her brain lesions were
secondary to malignancy. Brain metastases are considered to be the most common cause of intracranial cystic
lesions.
Case presentation: We present the case of a 60-year-old Canadian-born Caucasian woman with a subacute history
of ataxia, lower extremity hyper-reflexia, and otalgia who resided near a pig farm for most of her childhood.
Computed tomography and magnetic resonance imaging showed that she had multiple heterogeneous intracranial
cysts, suggestive of neurocysticercosis. Despite a heavy burden of disease, serological tests for cysticercosis were
negative. This result and a lack of the central scolices on neuroimaging that are pathognomonic of neurocysticercosis
prompted whole-body computed tomography imaging to identify another etiology. The whole-body computed
tomography revealed right hilar lymphadenopathy associated with soft tissue nodules in her chest wall and abdomen.
A biopsy of an anterior chest wall nodule demonstrated high-grade poorly differentiated carcinoma with necrosis,
which stained strongly positive for thyroid transcription factor-1 and synaptophysin on immunohistochemistry. A
diagnosis of stage 4 metastatic small cell neuroendocrine carcinoma was made and our patient was referred for
oncological palliative treatment.
Conclusions: This case illustrates the importance of the diagnostic approach to intracranial lesions. Our patient’s
diagnosis of neuroendocrine carcinoma was delayed because of her nontraditional presentation. Despite extensive
metastatic burden, the lack of perilesional edema and the identification of lesions appearing to be in various stages of
development led to a pursuit of neurocysticercosis as the diagnosis. The absence of constitutional symptoms should
not discount the possibility of malignancy from the differential diagnosis.
Keywords: Neurocysticercosis, Brain, Cysts, Adenocarcinoma, Metastases

Background
Cysticercosis occurs after the ingestion of eggs from
Taenia solium (pork tapeworm). Passage through the
gastrointestinal tract dissolves the coating around the
eggs, thereby allowing the cystic larvae to disseminate to
different sites in the body.

* Correspondence: john.c.lam@ucalgary.ca
1
Department of Medicine, The University of Calgary, Calgary, AB T2N 2T9,
Canada
Full list of author information is available at the end of the article

Neurocysticercosis involves the migration and development of such larvae within the brain or extraparenchymal tissue. Seizures, headache, and findings of increased
intracranial pressure are common manifestations of neurocysticercosis. On radiography, neurocysticercosis is
characterized by multiple intracranial cysts in different
stages of development. While the incidence of the disease
in Canada remains low, neurocysticercosis continues to be
the most common cause of seizures in developing countries [1].

© 2016 Lam et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Lam et al. Journal of Medical Case Reports (2016) 10:144

Fig. 1 Computed tomography of the head demonstrated multiple
bilateral well-defined cystic structures of different sizes associated
with calcification without perilesional edema

Case presentation
A previously healthy 60-year-old Caucasian woman presented to our hospital with a year-long history of rightsided otalgia diagnosed as otitis media. Despite multiple
courses of antibiotics, the symptoms persisted. Two
months prior to admission, she complained of difficulty
balancing and non-specific spontaneous involuntary
movements in her lower extremities. She had no history

Page 2 of 4

of seizure or headache. She reported no constitutional
symptoms or respiratory complaints. Her past medical
history was significant for a 60-pack year smoking history.
Our patient was born in rural Western Canada and
moved to Eastern Canada as a child. She resided with her
family adjacent to a pig farm but did not work directly with
livestock. She returned to rural Western Canada as a
young adult and was living there at the time of admission.
She has never travelled outside of North America. She had
no family history of neurological conditions or malignancy.
A neurological examination (including a fundoscopy)
demonstrated normal cranial nerves. Sensory and motor
examinations were unremarkable. Examination of her reflexes revealed hyper-reflexia (without muscle spread)
throughout her lower extremities. Bilateral ankle clonus
was present (greater than six beats) along with fasciculation in her right hand. A positive Romberg’s sign and a
wide-based ataxic gait were also noted. Cardiovascular and
respiratory examinations were unremarkable and chest
radiography performed prior to admission was normal.
Computed tomography (CT) of our patient’s head
demonstrated multiple bilateral well-defined cystic lesions involving both her supratentorial and infratentorial
regions. The cysts were mostly thin-walled of varying
sizes, and some were calcified. No paralesional edema or
mass effect was present (Fig. 1).
Magnetic resonance imaging of her brain with gadolinium contrast confirmed the presence of over 30 intracranial cystic lesions with differing fluid levels (Fig. 2a, b).
Radiographic findings were consistent with multiple stages
of neurocysticercosis evolution. However, no intra-lesional
scolices or extraparenchymal involvement were seen. A
skeletal survey was performed to assess for peripheral calcified lesions, with negative results. Our patient was diagnosed with presumptive neurocysticercosis and empirically

Fig. 2 a, b Magnetic resonance imaging of the brain demonstrated multiple bilateral intracranial cystic lesions within the subarachnoid space
and parenchyma. Differing signal intensities and fluids levels present on these cystic structures initially suggested neurocysticercosis in multiple
stages of evolution

Lam et al. Journal of Medical Case Reports (2016) 10:144

started on albendazole, prednisone, and seizure prophylaxis
while awaiting results from tests for T. solium serology.
Results of laboratory investigations, including renal
function, hepatic enzymes, and cerebrospinal fluid analysis, were all within normal limits. When results of the
cysticercosis serological tests came back negative despite
an extensive burden of brain disease, whole-body CT
was performed to check for other lesions that would be
more amenable to biopsy.
Whole-body CT revealed right hilar enlargement (2 × 3
cm) associated with soft tissue nodules in her chest wall
and abdomen. Equally concerning were infiltrates with irregular density along both adrenal glands and a low-density
mass arising from the lateral capsule of her left kidney.
A biopsy of an anterior chest wall nodule demonstrated high-grade poorly differentiated carcinoma with
necrosis (Fig. 3). The specimen stained strongly positive
for thyroid transcription factor-1 and synaptophysin on
immunohistochemistry (Fig. 4). A diagnosis of stage 4
metastatic small cell neuroendocrine carcinoma was
made and our patient was referred for medical and
oncological palliative radiation treatment. With palliative
oncological therapies, her ataxia improved transiently
but the spread of her malignancy continued, leading to
her death 9 months after her original diagnosis.

Discussion
Cysticercosis occurs after ingestion of eggs from T.
solium (pork tapeworm). The coating around the eggs is
dissolved by the gastrointestinal tract, allowing them to
enter the bloodstream and be distributed to other tissues
of the host. The cystic larvae (cysticerci) develop in multiple sites but are commonly found in the central

Page 3 of 4

Fig. 4 Neoplastic cells demonstrated strong diffuse nuclear positivity
for thyroid transcription factor-1 (TTF-1) by immunohistochemistry
(200× magnification). TTF-1 positivity is most frequently observed in
neuroendocrine neoplasms of pulmonary origin

nervous system (brain, spinal cord, ventricles) and skeletal muscle. Neurocysticercosis occurs when larvae migrate and develop in the brain or extraparenchymal
tissue. Seizures and headache are usually associated with
parenchymal cysts whereas extraparenchymal cysts are
characterized by findings of increased intracranial pressure. Neurocysticercosis is the most common cause of
seizures in developing countries [1].
Larvae remain viable for years, and multiple mechanisms of host immune tolerance have been postulated.
While some larvae succumb to the host’s inflammatory
reaction and form a granuloma in defense, other cysticerci do not. In the initial colloidal stage, the pathognomic finding of a cysticerci scolex within a thin-walled
cystic lesion may be seen. In later stages, the walls
thicken, calcify, and form a granuloma around the nonviable parasite. Imaging findings in neurocysticercosis
differ depending on the stage of cyst development. Neuroimaging will commonly reveal multiple cysts in different developmental stages [2].
There is a broad range of etiologies for intracranial cystic lesions found on imaging (Table 1). Brain metastases
Table 1 Differential diagnosis for intracranial cystic lesions [7, 8]

Fig. 3 High power (400×) magnification of the chest wall biopsy
confirmed dense crowding of neoplastic cells with small to medium
sized overlapping and molded nuclei, and limited cytoplasm. Nuclear
hyperchromasia with stippled chromatin lacking prominent nucleoli
can be seen. An area of necrosis is well visualized in the lower left
corner of the image

Malignant neoplasm:
Inflammatory:
• Metastatic lesion
• Multiple sclerosis
• Primary brain neoplasm (central nervous
• Acute disseminated
system lymphoma, glioblastoma)
encephalomyelitis
Infection:
• Transverse myelitis
• Bacterial (tuberculosis, pyogenic abscess,
• Neuro-Behçet’s disease
syphilis, nocardia, Whipple’s disease)
Other:
• Endemic fungi (cryptococcus,
• Neurosarcoidosis
coccidiomycosis, aspergillosis, histoplasmosis)
• Amyloidosis
• Parasitic (neurocysticercosis, cerebral
sparganosis)
• Viral (progressive multifocal
leukoencephalopathy)

Lam et al. Journal of Medical Case Reports (2016) 10:144

are the most common cause of intracranial cystic lesions, with lung cancer being the most common primary
tumor [3]. Clinically, only two-thirds of patients with
brain metastases are symptomatic: headache and mental
change are the commonest symptoms, and hemiparesis
and altered mental status are the most frequent signs
identified [4]. Classically, metastatic brain lesions appear
as multiple solid enhancing masses that are well delineated with smooth borders and extensive edema. Mass
effect and areas of central necrosis are common [5].
Smaller lesions may be associated with less perilesional
edema.
It is important to consider metastatic disease when
intracranial lesions are identified on imaging and to
commence a workup for primary pathology. In situations
of unknown but suspected primary malignant processes,
a chest radiograph or CT of the chest is a reasonable
starting investigation [6]. Our patient’s diagnosis of
bronchogenic carcinoma was delayed because of her
nontraditional presentation. Despite extensive metastatic
burden, the lack of perilesional edema and the finding of
lesions that appeared to be in various stages of development led to the pursuit of a neurocysticercosis diagnosis
and empirical treatment. The absence of constitutional
symptoms should not discount the possibility of malignancy from the differential diagnosis.

Page 4 of 4

The University of Calgary, Calgary, AB T2N 2T9, Canada. 4Foothills Medical
Center, The University of Calgary, 1403 29 Street NW, Calgary, AB T2N 2T9,
Canada.
Received: 29 December 2015 Accepted: 25 April 2016

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Conclusions
Intracranial lesions have a broad differential diagnosis
with brain metastases continuing to be the commonest
cause in the developed world. Our case emphasizes the
importance of a systematic approach when working up
the etiology of intracranial lesions and of having a low
threshold to investigate for malignancy.
Abbreviation
CT: computed tomography.
Acknowledgements
The authors have no disclosures to make. No funding was utilized for this
report.
Authors’ contributions
All authors were involved in management of the patient. JCL and SR drafted
the manuscript. AS performed the histological examination of the tissue. SV
oversaw manuscript preparation and revisions. All authors read and
approved the final manuscript.
Competing interests
The authors declare that they have no competing interests.
Consent
Written informed consent was obtained from the patient for publication of
this case report and accompanying images. A copy of the written consent is
available for review by the Editor-in-Chief of this journal.
Author details
1
Department of Medicine, The University of Calgary, Calgary, AB T2N 2T9,
Canada. 2Department of Pathology and Laboratory Medicine, The University
of Calgary, Calgary, AB T2N 2T9, Canada. 3Department of Infectious Disease,

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