English

Abstract

Crisoid aneurysms of scalp are rare extracranial arteriovenous malformation which presents as varicoid scalp swelling which gradually increases in size over time, and has high propensity for massive hemorrhage. Multidetector computed tomography is very useful in its evaluation and treatment planning, particularly when the feeding vessels and draining channels have both intra and extracranial course. We are reporting a case of 22-year-old female patient presented with varicoid pulsatile swelling in parieto-occipital region of the scalp with gradual progression in size. INTRODUCTION: Crisoid aneurysm is an extracranial arteriovenous malformation of scalp. It is congenital in about 80% of cases and traumatic in about 20% of cases. The congenital variety occurs as a result of faulty differentiation of the primitive vessel complex with persistence of primitive arteriovenous interconnections which are normally replaced by an intervening capillary bed (2, 7). The feeding arteries and veins of the lesion are the naive vessels which are massively dilated, because of hemodynamic alteration. These lesions can present as varicoid pulsatile swelling over the scalp which are progressively increasing in size and has propensity to massive hemorrhage. The lesion mostly supplied by external carotid artery branches, and drains into extracranial veins as well as dural sinuses through emissary veins. They are normally supplied by superficial temporal and occipital artery. The superficial temporal artery is frequently involved in traumatic crisoid aneurysm due to its long unprotected course. Angiography is gold standard investigation to delineate the lesion and to exclude an intracranial component. However this facility is not available at our institution. Multidetector computed tomography can be used in non-invasive diagnosis and treatment planning of this complex arteriovenous malformation.