DOI: 10.5137/1019-5149.JTN.11844-14.0

Case Report

Hemorrhagic Epidermoid Cyst in Cerebellar Vermis
Serebellar Vermis Yerleşimli Hemorajik Epidermoid Kist
Chuan-Yuan TAO1, Pan WEI2, Jia-Jing WANG3, Chao YOU1
1West China Hospital, Sichuan University, Department of Neurosurgery,Chengdu, Sichuan, China
2The 452nd Hospital of PLA, Department of Neurosurgery,Chengdu, Sichuan, China

3West China Hospital, Sichuan University, Department of Neurosurgical ICU, Chengdu, Sichuan, China

Corresponding Author: Chao YOU / E-mail: [email-masked]

ABSTRACT
Intracranial epidermoid cysts are usually located in the paramedian regions with characteristic imaging features. Intracystic hemorrhage is
rarely reported with most in the cerebellopontine angle area. We described a case of hemorrhagic epidermoid cyst in cerebellar vermis. The
patient was a 21-year-old male presenting with a first episode of convulsive seizure attack as the initial and sole symptom. Head computed
tomography showed a mass lesion in the cerebellar vermis with high density and nodular low density in the back of the lesion. Magnetic
resonance imaging revealed most of the lesion was hypointense to isointense, extremely hypointensity on T1-, T2-weighted imaging
respectively. The nodule was hyperintense on both T1- and T2-weighted images. The atypical clinical presentation, location and radiological
features of intracranial epidermoid cyst make accurate diagnosis quite challenging. In such cases, scrutinized histopathological examination is
necessary to exclude the malignancy that may need radio/chemotherapy.
Keywords: Cerebellar tumor, Cerebellopontine angle, Epidermoid cyst, Hemorrhage

ÖZ
İntrakraniyal epidermoid kistler genellikle paramedian bölgelere yerleşirler ve karakteristik görüntüleme özellikleri vardır. İntrakistik hemoraji
nadiren rapor edilmiştir ve bunların çoğunluğu serebellopontin açı yerleşimlidir. Serebellar vermis yerleşimli bir hemorajik epidermoid kist
olgusunu sunuyoruz. Olgu, ilk ve tek semptomu konvülzif epileptik atak olan 21 yaşında erkek hastadır. Kraniyal bilgisayarlı beyin tomografisi
serebellar vermisde yüksek dansiteli kitle lezyonunu gösterirken, lezyonun arka kısımları ise nodüler tarzda ve düşük dansiteli idi. Manyetik
rezonans görüntüleme ise T1 ağırlıklı kesitlerde hipointensden izointense doğru uzanan bir lezyonu gösterdi. T2 ağırlıklı kesitlerde ise
belirgin şekilde hipointensite mevcuttu. Nodül ise T1 ve T2 kesitlerde hiperintens idi. Atipik klinik başlangıç, yerleşim ve radyolojik özellikleri
intrakraniyal epidermoid kistlerin kesin tanısını zorlaştırmaktadır. Sunduğumuz olguda dikkatli bir histopatolojik inceleme radyo/kemoterapi
gerektiren malign tümörleri ekarte etmek açısından oldukça önemli idi.
ANAHTAR SÖZCÜKLER: Serebellar tümör, Serebellopontin açı, Epidermoid kist, Hemoraji

INTRODUCTION
Intracranial epidermoid cyst represents approximately
0.2 to 1% of all intracranial tumors (3).They usually occur
laterally. The most common location in the posterior fossa is
the cerebellopontine angle (CPA) area. The fourth ventricle
and cerebellar hemisphere location are also occasionally
reported. However, occurrence in the cerebellar vermis is
exceptionally rare (3, 4). We present a vermian epidermoid
tumor with intracystic hemorrhage. The initial symptom was
seizure and the radiologic imaging was unusual. We discussed
the possible reasons for the atypical manifestations and
emphasized the importance of histological examination.
CASE REPORT
A 21-year-old male soldier experienced a first episode of
convulsive seizure attack when singing. On admission,
he was alert without significant headache or cerebellar
signs. Computed tomography (CT) of the brain disclosed
a hyperdense mass lesion in the cerebellar vermis and
obstructive hydrocephalus. A small portion within the lesion
was found low in density (Figure 1a). Most of the lesion on

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magnetic resonance imaging (MRI) was hypointense to
isointense on T1-weighted images and extremely hypointense
on T2-weighted images (Figures 1b, c). Enhancement was not
noticed (Figure 1d). The nodule in the back of this lesion was
heterogeneously hyperintense on both T1 and T2 weighted
images, also absent of contrast enhancement.
He underwent midline suboccipital craniotomy. After opening
the dura, an extra-axial mass with a transparent capsule was
seen. We identified mud-like chronic hematoma in brown
color and yellow lipid debris when the capsule was cut open
(Figure 2a). During surgery, the lesion was totally removed;
no hair or obvious calcification or ossification was observed.
Postoperative course was uneventful. Histological
examination showed keratin, stratified squamous epithelium
and blood. Exhaustive looking for skin adnexal structures
or tissue derived from mesoderm or endoderm as well as
malignant elements failed. Epidermoid cyst accompanying
hemorrhage was confirmed (Figure 2b). The patient recovered
well with no morbidity. At 1-year follow up, MRI of brain
revealed disappearance of hydrocephalus and the lesion.
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Tao CY. et al: Vermian Hemorrhagic Epidermoid Cyst

DISCUSSION

location followed by the forth ventricle in the posterior fossa,
where trigeminal neuralgia, hearing loss and gate ataxia are
the main symptoms (1). The lesion in cerebellar vermis is
extremely rare (1, 2). In our case, chronic hemorrhage may
be responsible for the relatively young age at the disease

Intracranial epidermoid cyst is a congenital lesion with a
slow, long clinical course and an average age at diagnosis
around 40 years (1). The CPA region is the most common

A

c

A

b

Figure 1: a) Head CT showed a mass lesion
in the cerebellar vermis with high density
and nodular low density in the back of the
lesion. b) On axial T1-weighted MRI, the
53 ×55×48mm lesion was hypointense to
isointense and the nodule was hyperintense.
c) Axial T2-weighted MRI shows extremely
hypointensity of the lesion and the nodule is
heterogeneously hyperintense.
d) No enhancement is observed on sagittal
contrast T1-weighted MRI.

d

b

Figure 2: a) Photograph during operation revealed mud-like old hemorrhage and yellow lipid debris (arrow). b) Histological
examination showed keratin, stratified squamous epithelium and blood, consistent with hemorrhagic epidermoid cyst (HE, ×200).
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Tao CY. et al: Vermian Hemorrhagic Epidermoid Cyst

onset due to accelerated growth of the lesion. In addition,
seizure attack became the single presentation, probably
induced by singing which contributed to the acute elevation
of intracranial pressure in the setting of hydrocephalus. It was
different from the report by Singh et al. in which the patient
presented seizure in sleep because of acute hemorrhage of
epidermoid cyst in the supratentorial compartment (5).
The radiological manifestation of our case was quite atypical.
It has been reported that intratumoral hemorrhage is the
most common cause of changes in the signal intensity (1,
4). Meanwhile, the signal intensity on MR imaging varies
depending on the contents. Hyperintensity on both T1and T2-weighted images can be due to a semi-liquid cystic
content with high protein concentration; high signal intensity
on T1-weighted and low signal intensity on T2-weighted
images can be caused by even thicker toffee-like content with
a combination of high protein content and high viscosity;
low signal intensity on T1- and T2-weighted images can be
attributed to an unusual composition of epithelial debris,
crystals of cholesterol, and keratin (1). In our case, the signal
intensity of most of the lesion partly accords with that of
chronic hematoma while the signal feature of the nodule may
be related to the intracystic content of high protein.
When epidermoid cyst occurs in the cerebellar vermis with
hemorrhage, preoperative misdiagnosis is quite frequent
(1, 4). Surgeons should recognize its uncommon features to
avoid surgical complications such as chemical meningitis.
Additionally, careful histological examination is essential to
differentiate from other diseases such as immature teratoma
and to detect malignant transformation which requires
adjuvant therapy after surgery (2).

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CONCLUSION
Vermian epidermoid cyst is very rare and can have seizure
as the sole clinical presentation. When complicating with
hemorrhage, the differentiation from other entities is
difficult by preoperative imaging features. Scrutinized
histopathological examination is necessary to exclude the
malignancy which may need radio/chemotherapy.
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3. Raghunath A, Devi BI, Bhat DI, Somanna S: Unusual
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2013
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