Huang et al. BMC Medical Imaging
(2019) 19:79
https://doi.org/10.1186/s12880-019-0382-9

CASE REPORT

Open Access

Ataxia as the main manifestation of tumorlike primary angiitis of the central nervous
system: a case report and literature review
Yu-Jing Huang, Li Zhang, Ying Mao and Guang-Xian Nan*

Abstract
Background: Primary angiitis of the central nervous system (PACNS) is a rare disease, and tumor-like primary
angiitis of the central nervous system is even rarer. Histopathology is the gold standard for tumor-mimicking
PACNS. However, pathological diagnosis is relatively limited due to fewer biopsy opportunities.
Case presentation: A 68-year-old male presented with ataxia, and was diagnosed with tumor-like primary angiitis
of the central nervous system. The patient underwent Intravenous drip glucocorticoid therapy (10 mg of dexamethasone,
daily). After 10 days, the symptoms of the patient were completely relieved. Radiology revealed that the low density
lesion in the right cerebellar hemisphere obviously narrowed. Cyclophosphamide therapy was not initiated.
Conclusion: It is crucial for clinicians to be aware of changes in radiology that indicate PACNS, since the diagnosis of
tumor-like PACNS remains quite challenging. Glucocorticoid therapy is an effective therapy in this condition, and the
prognosis can be favorable.
Keywords: Ataxia, Tumor-like primary angiitis of the central nervous system, Brain MRI examination,
Glucocorticoid therapy

Background
Primary angiitis of the central nervous system (PACNS) is
a rare disease. The etiology of this disease remains
unknown, and it has no correlation with infection and
autoimmunity. PACNS mainly affects the small or
medium vessels (arteries or veins), and the leptomeninges
of the brain and spinal cord. A subtype of PACNS is called
tumor-like PACNS, in which the imaging features a
solitary tumor-like mass lesion. In order to improve the
early diagnosis and identification of tumor-mimicking
PACNS, one case of tumor-like PACNS in our hospital, in
which ataxia was the main manifestation, was reported.
Case presentation
A 68-year-old male was admitted to our hospital due to
dizziness and unstable walking. The patient also complained of headache, which persisted for the whole duration
of the disease. Furthermore, the patient had a history of
* Correspondence: nan_guang_xian@163.com
Department of Neurology, China-Japan Union Hospital of Jilin University,
No.126 Xiantai Street, Changchun 130033, Jilin, China

hypertension and diabetes, traumatic splenectomy, and
gout.
The physical examination revealed a blood pressure (BP)
of 180/90 mmHg (normal range: 80–120/60–80 mmHg).
Furthermore, the patient’s right eyeball abduction was
restricted, the right finger test was less stable, and the right
side and knee tibia test were less stable.
The laboratory investigations indicated a white blood
cell (WBC) count of 12.56 × 109/L (reference range: 4–
10 × 109 cells/L), a lymphocyte count of 4.86 × 109 cells/L
(0.8–4.0 × 109 cells/L), and a monocyte count of 0.92 × 109
cells/L (0.12–0.80 × 109 cells/L). Furthermore, blood sugar
was 9.53 mmol/L, urine glucose was 2+, triglyceride was
7.2 mmol/L (< 1.7 mmol/L), and total cholesterol was 7.18
mmol/L (3.00–5.70 mmol/L).
Lumbar puncture and cerebrospinal fluid (CSF) analyses were performed. CSF pressure was 130 mmH2O,
CSF WBC count was 6 × 109 cells/L (0–8 × 109 cells/L),
CSF glucose was 3.2 mmol/L (2.2–3.9 mmol/L), CSF
protein was 0.2 g/L (0.12–0.60 g/L), and CSF chloride
was 127.2 mmol/L (120–132 mmol/L).

© The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
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(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Huang et al. BMC Medical Imaging

(2019) 19:79

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Fig. 1 a. The brain CT scan revealed a large area of low-density
lesion in the right cerebellar hemisphere. b. The brain MRI T1
weighted image revealed a large area of long T1 signal in the right
cerebellar hemisphere with an obvious space-occupying effect. The
brain stem and fourth ventricle were obviously pressed, and moved
slightly to the left. c. The brain MRI T2 weighted image revealed a
large area of long T2 signal in the right cerebellar hemisphere, with
an obvious space-occupying effect. The brain stem and fourth
ventricle were obviously pressed, and moved slightly to the left. d.
The brain MRI FLAIR weighted image revealed a large area of
hyperintense signal in the right cerebellar hemisphere, with an
obvious space-occupying effect. The brain stem and fourth ventricle
were obviously pressed, and moved slightly to the left. e. The brain
MRI T1 weighted image enhanced sequence revealed that the
lesions in the right cerebellar hemisphere were markedly enhanced
by contrast media

The brain computed tomography (CT) result revealed a
low density lesion in the right cerebellar hemisphere. The
3.0 T magnetic resonance imaging (MRI) was used to
obtain the T1-weighted image, T2-weighted image, fluidattenuated inversion recovery (FLAIR), diffusion weighted
image (DWI), susceptibility weighted imaging (SWI), magnetic resonance angiography (MRA), magnetic resonance
spectroscopy (MRS), and T1-weighted image enhanced
sequence. The brain MRI suggested that the lesion had
long T1 and T2 signals, and a high signal in the FLAIR
image. The brain stem and fourth ventricle were obviously
pressed, and moved slightly to the left. The DWI was not
abnormal, and the MRA did not reveal any apparent
anomalies. The SWI revealed a marked low signal on the
lesion, the boundary was clear, and the phase map had a
high and low mixed signal, which indicated a micro
hemorrhage. The MRI enhancement in the brain revealed
the lateral marginal margin of the right cerebellar hemisphere, in which the obvious enhancement area of the
plaque was visible, the local cerebellar gyrus was clear,
and the right cerebellar hemisphere was visible with a strip
and tortuous vascular shadow. No obvious inflammatory
lesions were found in the chest CT. The MRS revealed a
right cerebellar hemisphere lesion (PRESS, TR = 2000 ms,
TE = 30 ms, 135 ms). Furthermore, the N-acetyl aspartate
(NAA) peak and creatinine (Cr) had no significant change,
the choline (Cho) peak increased, NAA/Cr = 1.05, Cho/
Cr = 1.53, and Cho/NAA = 0.95 (Figs. 1, 2, 3).
Additional tests were performed to exclude any
underlying systemic disease or alternative diagnoses
(− for negative, + for positive):
1. Systemic rheumatic diseases:
Serum Antinuclear antibodies (ANA), 1:100 (−);
dsDNA antibodies, (−);
Antiphospholipid antibodies-Lupus anticoagulant
(LA), (−);
Anticardiolipin (aCL) antibodie, (−);

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Fig. 2 a. The brain CT scan after 10 days of treatment revealed that
low-density lesions in the right cerebellar hemisphere were
attenuated. b. The brain MRI T1 weighted image after 10 days
revealed a less long T1 signal in the right cerebellar hemisphere. c.
The brain MRI T2 weighted image after 10 days revealed that a long
T2 signal in the right cerebellar hemisphere attenuated. d. The brain
MRI FLAIR weighted image after 10 days revealed that a hyperintense signal in the right cerebellar hemisphere attenuated. e. The
brain MRI T1 weighted image enhanced sequence revealed that
there were less lesions in the right cerebellar hemisphere

Anti-beta2 glycoprotein (GP) antibodies, (−);
Antineutrophil cytoplasmic antibodies (ANCA), (−);
Serum C3: 0.96 g/L, (normal range: 0.9–1.5 g/L);
Serum C4 0.24 g/L, (0.2–0.4 g/L);
IgG, 9.3 g/L (8–16 g/L); IgM, 1.13 g/L (0.5–2.2 g/
L); IgA, 1.99 g/L (8–16 g/L).
2. Infectious diseases:
Syphilis: Venereal disease research laboratory
(VDRL), (−);
Rapid plasma reagin (RPR), (−); T. pallidum
particle agglutination assay (TPPA), (−);
Tuberculosis (TB): Acid-fast bacilli smear and
mycobacterial culture, (−); Chest CT for
pulmonary TB infection, (−); TB-PCR test, (−);
Hepatitis B and C viruses: Serum antigen and
antibody tests, (−);
Human Immunodeficiency Virus (HIV): Serum
antibody test, (−).
Since no alternative diagnosis was achieved, according
to the results of the brain MRI scan and functional imaging, the suspected diagnosis was PACNS, and an intravenous infusion of 10 mg of dexamethasone per-day was
given for the consecutive 10 days. After steroid therapy,
the symptoms of the patient were completely relieved.
The brain CT revealed that the low density lesion of the
right cerebellar hemisphere obviously narrowed, and the
standard and enhanced MRI scan were re-checked. The
plaques were long T1 and T2 signals, the FLAIR was
slightly high, and the enhanced scan revealed a flaky
enhancement. Thus, cyclophosphamide therapy was not
initiated.

Discussion
The first symptom of the present case was ataxia. Even
though the blood lymphocyte and monocyte counts
were slightly elevated, none of the symptoms or tests
(including the CSF analysis) indicated infection. Furthermore, the results of the laboratory examination did
not support syphilis or other infections, leukemia, antiphospholipid antibody syndrome, or other rheumatic
disease that may cause vasculitis. In addition, disease-

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Fig. 3 a. There was no abnormality in the magnetic resonance
angiography. b. The diffusion weighted image revealed a large area
of low-density lesion in the right cerebellar hemisphere. c. The
susceptibility weighted imaging revealed multiple punctate microbleeding lesions in the right cerebellar hemisphere. d. The magnetic
resonance spectroscopy revealed that the N-acetyl aspartate (NAA)
peak and creatinine (Cr) had no significant changes, the choline
(Cho) peak increased, NAA/Cr = 1.05, Cho/Cr = 1.53,
and Cho/NAA = 0.95

like chronic lymphocytic inflammation with pontine
perivascular enhancement responsive to steroids (CLIPPERS) were excluded for the non-conformity of the MRI
(the lesion of the CLIPPERS scattered throughout the
pons with variable involvement of the medulla, brachium pontis, cerebellum, midbrain and spinal cord).
Combined with imaging examination, the preliminary
clinical diagnosis of PACNS can be made, since no secondary vasculitis or alternative diagnoses was present.
Although the patient could not cooperate with the
pathological biopsy, the patient’s symptoms improved
after steroid therapy, and the imaging of the lesions
significantly improved, which further supported the
PACNS diagnosis.
PACNS was proposed for the first time as an independent disease by Cravioto et al. in 1959 [1]. In 2008, a
new subtype of tumor-like primary angiitis of the central
nervous system [2] was proposed by Molloy et al. after
summarizing the information of 38 patients with tumorlike lesions and the pathological examination of PACNS.

Clinical manifestation
The incidence of PACNS is 2.4/100 per year, and lump-like
PACNS accounts for 5–15% [3] of PACNS. This can occur
at any age, with no gender preference. Furthermore, the
clinical manifestations are correlated to the size of the involved vessel and the pathological type of vasculitis. Headache, cognitive impairment and persistent focal neurological
deficits or stroke are the most common clinical manifestations of PACNS [4]. Headache is the first symptom for a
mass-like tumor.

Laboratory examination
The laboratory examination was not specific and sensitive, the erythrocyte sedimentation rate was 2–3 times
higher than the normal value, and the serum autoantibodies were mostly negative [5]. Cytosolic ANCA and
ANCA were weak positive [6] in some patients. Furthermore, 90% of the results of the cerebrospinal fluid of
PACNS patients were abnormal, and the protein content
and number of WBC could be mild to moderate.

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Imaging features
Brain CT examination

One-third to two-thirds of PACNS patients can present
different degrees of abnormal low density signals, and its
sensitivity is lower than MRI.
Brain MRI examination

MRI T1 weighted images, T2 weighted images and fluid
attenuated inversion recovery sequences are highly sensitive to lesions, but lack specificity. PACNS is mainly
observed in unilateral supratentorial lesions (frontal lobe,
temporal lobe, occipital lobe and parietal lobe), with the
frontal lobe as the center.
MRI enhanced scans can monitor blood flow changes,
and the thickening and intensifying of the blood vessel wall
at the early stage. The characteristics of focus enhancement
are more common in unilateral supratentorial cerebral
hemispherical mass enhancement, which can be reinforced
with banded and linear, and are partly accompanied by
edema and an occupying effect, and the midline displacement is also visible.
DWI usually presents with a high signal, and the apparent diffusion coefficient has a low signal. It is difficult to
identify some diseases simply with DWI. In practice, it is
necessary to comprehend the characteristics of the change
in DWI signal as disease evolving, and improve its value in
the diagnosis of lump-like PACNS.
MRS has important clinical significance for the evaluation of lesions, such as PACNS. The Cho/Cr, Cho/NAA,
lipid and lactic acid peaks were all increasing. It has also
been reported that the peak value of glutamate and glutamine in the MRS of PACNS patients is significantly
higher. Panchal et al. [7] further inferred that glutamine
synthetase is activated under inflammatory reactions, and
that the glutamic acid produced by glutamic acid is
increased.
SWI is important in diagnosing PACNS. Its magnetic
susceptibility differential imaging based on blood oxygen
saturation has great advantages in hemorrhage and small
vessel imaging. Since the blood vessels of PACNS patients
were liable to rupture and hemorrhage, SWI would be
helpful for its diagnosis and differential diagnosis.
MRI perfusion imaging is a non-invasive method that
reflects the distribution and perfusion of tissue microcirculation. Tumor-mimicking PACNS can lead to a decrease in
local blood flow. The study conducted by Muccio [8] revealed that the PWI of PACNS has low perfusion, while the
PWI of gliomas has high perfusion. Therefore, PWI has
great significance in the identification of lesions, such as
PACNS and brain tumors.
Digital subtraction angiography

Few abnormal lesions were found. The typical changes included uneven thickness of the vessels, segmental stenosis,

Page 5 of 6

dilatation, vascular obstruction and delayed vascular emptying. However, there was a lack of specificity. Furthermore,
DSA cannot be used as a routine examination for lump-like
PACNS [9].

Brain tissue biopsy
Histopathological examination is the gold standard for
the diagnosis of PACNS, but the positive rate of brain
biopsy is only 25–50% [10]. PACNS histopathological
results can be divided into four types: granulomatous
vasculitis, lymphocytic vasculitis, necrotic vasculitis, and
beta amyloid-associated cerebral vasculitis (A beta-related
angitis, A beta RA) [11].
Diagnosis
Calabrese and Mallek proposed the diagnostic criteria in
1988 [12]. At present, this standard is still in use. The
details are as follows: (1) Clinical criteria. The patient’s
history or clinical examination suggests that there are
neurological deficits. (2) The criteria for imaging and
histology. The vasculitis of the central nervous system is
confirmed by imaging and/or pathology. (3) Exclusion
criteria. There is no evidence of systemic vasculitis, or
any evidence that the vasculitis is secondary, such as
syphilis associated vasculitis. All of the above conditions
should be met.
Treatment and prognosis
The treatment of PACNS has not been supported by randomized controlled trials. The recommended treatment is
glucocorticoid combined with immunosuppressive agents
[13]. However, there have been reports that the efficacy of a
steroid alone is better [14]. Usually, steroid therapy is initiated with 1 mg/kg of prednisone to a maximum of 80 mg/
day, or its equivalent. The dosage of steroids should be
tapered after four to 6 weeks of initial dosage, or according
to the finally reached dosage of 5 mg of prednisone, daily.
For the present patient, after being suspected and diagnosed
with PACNS, steroid alone was started, and the patient’s
symptom and radiology tests were closely monitored. After
10 days, the symptoms of the patient were completely
relieved, and lesions on MRI scan were alleviated. Thus,
cyclophosphamide therapy was not started.
Conclusion
When a patient has central nervous system symptoms and
the imaging findings are mass–like, but are not complete,
tumor-like PACNS should be taken into consideration, and
the laboratory and brain MRI examinations and functional
imaging should be further examined. It is crucial for clinicians to be aware of the changes in radiology, which indicate
PACNS, since the diagnosis of tumor-like PACNS is quite
challenging. Glucocorticoid therapy is an effective therapy
for this condition, and the prognosis can be favorable.

Huang et al. BMC Medical Imaging

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Abbreviations
BP: Blood pressure; DWI: Diffusion weighted image; FLAIR: Fluid attenuated
inversion recovery; MRA: Magnetic resonance angiography; MRS: Magnetic
resonance spectroscopy; NAA: N-Acetyl aspartate; PACNS: Primary angiitis of
the central nervous system; SWI: Susceptibility weighted imaging;
WBC: White blood cell
Acknowledgements
Not applicable.
Authors’ contributions
HYJ conceptualized and designed the study, drafted the initial manuscript,
and reviewed and revised the manuscript. ZL and MY designed the data
collection instruments, collected data, carried out the initial analyses, and
reviewed and revised the manuscript. NGX coordinated and supervised data
collection, and critically reviewed the manuscript for important intellectual
content. All authors approved the final manuscript as submitted and agree
to be accountable for all aspects of the work.
Funding
Not applicable.
Availability of data and materials
Not applicable.
Ethics approval and consent to participate
This study was conducted in accordance with the declaration of Helsinki.
This study was conducted with approval from the Ethics Committee of
China-Japan Union Hospital of Jilin University. A written informed consent
was obtained from all participants.
Consent for publication
A written informed consent was obtained from the patient for the
publication of this case report and any accompanying images. A copy of the
written consent is available for review upon reasonable request.
Competing interests
The authors declare that they have no competing interests.
Received: 26 April 2019 Accepted: 25 September 2019

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