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SCALP ARTERIOVENOUS MALFORMATION : A CASE REPORT
Wan Najwa Zaini Wan Mohamed, Noreen Norfaraheen Lee Abdullah,
Ahmad Sobri Muda*
Department of Radiology, School of Medical Sciences, Universiti
Sains Malaysia,Health Campus 16150 Kubang Kerian, Kelantan,
Malaysia
*Department of Radiology, Medical Centre, Universiti Kebangsaan
Malaysia,Jalan Yaacob Latif, Cheras, 56000 Kuala Lumpur,
Malaysia
We report a rare case of Arteriovenous malformation (AVM) of the
scalp in a 30year-old Malay gentleman who presented with painless
forehead swelling sincebirth. Magnetic Resonance Imaging (MRI) and
cerebral angiogram performedand the findings are discussed.
Key words : Scalp Arteriovenous Malformations, Subcutaneous
Arteriovenous malformations, Radiological features
Introduction
Arteriovenous malformation (AVM) in thescalp is rare when
compared with other subcutaneous
or cervicofacial vascular anomalies such as thehaemangioma or
venous malformations. It is anabnormal fistula communication
between feedingarteries and draining veins without intervening
Submitted-20-02-2005, Accepted-30-12-07
Malaysian Journal of Medical Sciences, Vol. 15, No. 3, July 2008
(55-57)
CASE REPORT
Figure 1 : The AVM has a bluishdiscoloration at the midline of
theforehead could be due to dilateddraining veins. The overlying
skinis coarse and dry; however therewas neither ulceration nor
activehemorrhage present.
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Figure 2 : MRI revealed subcutaneous mass at midline of
theforehead has inhomogeous signal intensities with flowvoid
serpinginous structures within in keeping withenlarged draining
veins. No intracranial extension.
Wan Najwa Zaini Wan Mohamed, Noreen Norfaraheen Lee Abdullah et.
al
capillary bed. The draining veins can dilate andcauses esthetic
problem (1-3). It usually presents inlate childhood, adolescent or
early adulthood. It canalso cause massive hemorrhages due to
dryness ofthe overlying skin and injuries (1). In this report
wedescribe the clinical and radiological features of apatient with
a scalp arteriovenous malformation.
Case Report
The patient was a 30 year-old Malaygentleman who complained of a
painless foreheadswelling since birth, increasing in size for the
past 3– 4 years. Initially, it was a reddish small growth.The
lesion bled once following trauma about a yearprior to admission.
The hemorrhage was secured atthat time without resorted to any
definitive treatment.Insidiously the forehead lesion grew in size
and
causing esthetic problem to him. There was nosimilar history in
the family.
On examination, there was a soft, bluish andnon-tender lesion in
the midline of the forehead. Theoverlying skin is coarse and dry;
however there wasneither ulceration nor active hemorrhage present
(fig1). Bruit was heard on auscultation of the lesion.The vital
signs are stable and all other systems werenormal. The blood
investigations wereunremarkable.
Magnetic Resonance Imaging (MRI) of thebrain revealed a
predominently hyperintensesubcutaneous mass in the midline of the
foreheadon both T1 and T2 weighted images which extendssuperiorly
beyond forehead and inferiorly down tothe root of nose. There are
mulriple flow voidserpinginous structures within the lesion
whichenhanced with contrast, in keeping with dilated
Figure 3 : Cerebral angiography revealed multiple feeding
arteries with tortouscourse arising from ophthalmic arteries and
also from superficialtemporal arteries.
57
vessels (fig 2). However, no MR angiography wasdone at that
time. There was no intracranialextension.
About 2 months after MRI, he underwentcerebral angiogram, which
showed presence ofabnormal early draining veins, in keeping
withvascular malformations in the midline frontal region.Feeding
arteries with tortous course appeared arisingfrom the right
ophthalmic artery with several otherfeeders from the left
ophthalmic artery. There arealso feeders also from right and left
superficialtemporal arteries (fig 3). No supply was noted fromboth
anterior cerebral arteries. Enlarged earlydraining veins were seen
draining into the scalpveins. There was no no intracranial venous
drainage.He then underwent surgery for complete removalof his scalp
AVM in the forehead.
Discussion
AVMs in scalp are relatively rare. They are20 times more common
in the brain involving orsupplied by intracranial vasculature than
in that fromexternal carotid arteries (1). Cervicofacialinvolvement
is most common in the cheeks, ears,nose, and less commonly forehead
(2). Scalp AVMsare normally noticed in late childhood, adolescentor
early adulthood, when substantial esthetic andsocial disturbance
entailed, or due to various stimulisuch as trauma, pregnancy or
puberty (2).
MRI is helpful to differentiate cervicofacialAVMs from other
vascular lesions and aid in thecorrect diagnosis as well as to
distinguish whetherthere is intracranial extension or involvement
(3).MRI can also help to distinguish scalp AVMs whichare high flow
lesions from other low flow lesionssuch as venous or lymphatic
malformations, and thiswill help with the treatment planning.
However,catheter angiography is still the gold standardmodality to
understand the angioarchitecture of thelesion and to exclude any
intracranial component(4).
Management of scalp AVMs is difficultbecause of its high flow,
complex vascular anatomyand cosmetic problems. There are various
techniquesand method of treatment for scalp AVMs. Amongthe
treatment options include surgical excision,ligation of feeding
vessels, transarterial andtransvenous embolization, injection of
sclerosantinto the nidus and electrothrombosis (1, 5-7). Shenoyet
al divided scalp AVMs into group 1 and II, tohelp decide the
treatment of choice. Group 1 willrepresent primary scalp vascular
malformations and
Group II will represent secondary scalp venousdilatations. This
patient belongs to group Irepresenting primary scalp vascular
malformations.
Surgical excision is the most common andsuccessful method of
treating scalps AVMs (1).Endovascular approaches are an option as
adefinitive therapy or as an adjunct to surgical therapyto reduce
blood loss during excision (5). The mostcommon cause of treatment
failure, even withcombined embolization and surgery is
incompleteresection. Recurrence has been reported as late as18
years after complete surgical resection (4).
Corresponding Author :
Dr. Ahmad Sobri Muda, MD(UKM), MMed (USM)Department of
Radiology, Hospital UniversitiKebangsaan Malaysia, Jalan Yaacob
Latif, Cheras,56000 Kuala Lumpur, MalaysiaTel: +603 91455555 (O)
019-6685885 (H/P)Fax: +603-91724530Email: [email protected]
References
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SCALP ARTERIOVENOUS MALFORMATION : A CASE REPORT
