Introduction

Recently, greater attention has been garnered on rare vascular malformations of the brain —“pure arterial malformations”—in both the adult and pediatric age groups [1,2,3,4,5,6,7,8,9]. Moreover, pure arterial malformations are thought to be associated with a benign natural history and should be treated conservatively. At times, these malformations may be mistaken for arteriovenous malformations (AVMs), arteriovenous fistulas (AVFs), or cerebral saccular aneurysms [2,3,4,5].

Incidental presentation of pure arterial malformation in otherwise healthy children has been less frequently described [9]. In this study, we describe the clinical course of one child over 12 months of follow-up.

Case report

History

Our patient is a 10-year-old boy who presented after a concussion suffered during a hockey game. He had no relevant past medical history. A noncontrast CT of the head (Fig. 1) suggests abnormal cerebral vasculature. The patient was otherwise asymptomatic.

Fig. 1
figure 1

CT head. a Coronal and b axial noncontrast head CT shows a hyperdense mass with eggshell calcifications in the region of the supraclinoidal segments of the internal carotid artery, suggestive of a vascular malformation

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Examination

Patient displayed a normal neurological examination without focal deficits. There was no pronator drift.

Diagnostic studies

Advanced imaging with CT angiogram (CTA) of the head (Fig. 2) revealed a tortuosity of vessels in the left internal carotid artery segments. Patient then underwent a diagnostic cerebral angiogram (Fig. 3). There was no aneurysm, AV fistula, or early venous phase drainage associated with this malformation.

Fig. 2
figure 2

CTA head. a Coronal, b sagittal, and c axial projections of the CTA head confirm a vascular malformation of the left cervical internal carotid artery (ICA), distal ICA, anterior cerebral artery, and fetal posterior cerebral artery

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Fig. 3
figure 3

Digital subtraction angiography of the left internal carotid artery (ICA) injection demonstrates vessel tortuosity in the cervical and distal ICA segments and a fetal posterior cerebral artery

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Clinical course

The patient did well throughout the year of follow-up and at 1 year after the procedure. He remained asymptomatic. There was no growth or change in the morphological appearance of the lesion based on follow-up CTA. Because our patient was asymptomatic with no changed based on noninvasive imaging, the risks of invasive conventional angiography did not seem warranted. He has also returned to playing hockey.

Discussion

Our case was consistent with the previously published incidental case of pure arterial malformation in a child (Table 1) [9].

Table 1 Incidental (italic type) and symptomatic cases of pediatric pure arterial malformation
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In one review [9], the authors found that the most common locations for pure arterial malformations were the ACAs and PCoA-PCA complex, as in our patient.

Catheter angiography is an important component to distinguish these entities. Differentiating between AVMs and AVFs, and pure arterial malformations is straightforward as there is no arteriovenous shunting in pure arterial malformations [4, 5].

The etiology of pure arterial malformations is unknown. Some hypotheses include an embryologic defect or insult during development of the intracranial arterial circulation resulting in dysplasia, segmental arterial vulnerability from an acquired insult such as viral infection or genetic mutation later in life, or a chronic healed traumatic dissection of a major intracranial artery [9].

Conservative management as a mainstay of treatment for pure arterial malformations is consistent with case reports and small case series published in the literature [2,3,4,5,6,7,8,9].

Conclusions

Pure arterial malformations are a rare type of brain vascular malformation in the pediatric patient population. Most reported cases have been associated with diseases such as viral infection, PHACE syndrome, and moyamoya disease. Incidental presentation in children is even less common. Diagnosis of these lesions may be challenging; however, catheter angiography may help ascertain the diagnosis of pure arterial malformation. Invasive treatment is generally not indicated. Management consists of surveillance with serial imaging such as MRA.