Carotid Artery Aneurysm and Hypomelanosis of Ito

INTRODUCTION
Hypomelanosis of Ito is a rare neurocutaneous syndrome characterized by hypopigmented skin lesions, abnormalities of the central nervous system, skeletal system, eyes and teeth.


CASE PRESENTATION
We present a case of a 4-year-old boy with hypomelanosis of Ito and neck pulsatile mass due to a giant left common carotid dissecting aneurysm.


DISCUSSION
To our knowledge, this is the first report of association of hypomelanosis of Ito with carotid aneurysm.


CONCLUSION
For children with hypomelanosis of Ito and abnormal neurologic findings, vascular neuroimaging should be considered.

A 4-year-old boy with hypomelanosis of Ito (HI) presented with a progressively growing, pulsatile neck mass. His parents denied trauma, and a physical examination showed hypopigmented cutaneous areas in the left neck, face, and chest (shown in Fig. 1) and a pulsating mass in the lower anterior neck. The CT angiography and selective angiogram showed a 12 mm × 60-mm left common carotid artery dissecting aneurysm, causing flow stagnation. The right carotid artery, vertebral arteries, and cerebral arterial circle (known as the circle of Willis) were normal. After balloon test occlusion confirmed adequate collateral flow, treatment was indicated to prevent thromboembolic events. Endovascular parent artery occlusion with coils was performed (shown in Fig. 2) and achieved aneurysm thrombosis, reducing the mass effect. He remained asymptomatic during a 1-year follow-up, with no cerebral ischemia and good exercise tolerance.
HI is a neurocutaneous disorder first described as incontinentia pigmenti achromians in 1952 by Minor Ito [1]. It is caused by genetic mosaicism or translocations, usually not inherited but occur during embryonic development due to postzygotic mutation [1]. Macular hypopigmented skin whorls and streaks karger@karger.com www.karger.com/pne following the lines of Blaschko characterize HI [1][2][3][4][5]. Neurological manifestations include psychomotor delay, epilepsy, microcephaly, and muscular hypotonia [1]. HI may also affect the musculoskeletal system, eyes, and teeth [1][2][3][4][5]. Additional manifestations encompass deafness, hemihypertrophy, precocious puberty, and genitourinary abnormalities [1]. Cardiovascular involvement is uncommon, but abdominal aortic hypoplasia and atrial and ventricular septal defects can be found [2,3]. Neurovascular anomalies are infrequent and primarily associated with moyamoya syndrome and brain arteriovenous malformation [3,4]. Although it is not clear whether that is an incidental finding, the concurrent occurrence of a carotid aneurysm and HI might have a syndromic relationship, which opens a new line of inquiry.
Asymptomatic carotid occlusions have a good prognosis and low ischemic stroke risk [6]. Nevertheless, long-term imaging follow-up is recommended to detect additional abnormalities.
Since neurocutaneous disorders may have heterogeneous systemic involvement, further studies are needed to confirm the possibility of carotid artery involvement in HI. In addition to conventional MR sequences, specific vascular neuroimaging should be considered for children with HI and abnormal neurological findings to prevent a misdiagnosis [7].

Statement of Ethics
This study was conducted ethically following the World Medical Association Declaration of Helsinki. This retrospective review of patient data did not require ethical approval in accordance with local guidelines. Written informed consent for publication of data and images was provided and signed by the patient's guardian.

Conflict of Interest Statement
The authors have no conflicts of interest to declare.

Funding Sources
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Author Contributions
Zeferino Demartini Jr. and Gelson Luis Koppe: conception of the work; Bernardo C.A. Teixeira: acquisition of the data; Zeferino Demartini Jr., Gelson Luis Koppe, and Bernardo C.A. Teixeira: analysis and interpretation of the data, drafting of the work, critical revision of the work for intellectual content, final approval of the version to be published, and accountable for all aspects of the work and ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Data Availability Statement
All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author.