Arteriovenous fistula of the mandible simulating an odontogenic cyst. A case report

Abstract

We describe a rare case of mandibular highflow arteriovenous malformation (AVM) mimicking an odontogenic cyst in a young man. The diagnosis of mandibular AVM was made by CT angiography and confirmed by digital subtraction angiography. CT scan showed the extent of mandibular bone alteration and a double enlarged mandibular canal on the same side. An AVM containing a large aneurysm was demonstrated by CT angiography.The mandibular AVM was successfully treated by endovascular therapy with Guglielmi detachable coils. On panoramic radiogram, mandibular AVMs can appear as cystic lesions without pathognomonic features. Several benign and malignant tumours of this anatomical region must be considered in the differential diagnosis.We emphasize the radiological sign of double enlarged mandibular canal and the diagnostic role of CT, particularly CT angiography, to discriminate a mandibular AVM from neoplastic entities of this region, sparing the risks of a needle biopsy.

Figure 1

Panoramic radiograph (A), axial (B) and parasagittal (C) CT scan with bone algorithm. "Benign" lytic lesion in the right mandibular body (asterisk);double mandibular channel on the same side (arrow).

Figure 2

CT angiography axial (A) and parasagittal (B) images. Aneurysmal dilatation of a vessel is visible within the mandibular bone lesion (asterisks). An enlarged inferior alveolar artery and vein are also visible within the mandibular channel (arrow).

Figure 3

CT angiography parasagittal VRT images (A,B) allow a three-dimensional, concomitant evaluation of both vascular and osseous alterations.

Figure 4

Digital subtraction angiography. A) Selective catheterization of the external carotid artery common trunk shows the arteriovenous malformation supplied by a split inferior alveolar artery. A 2 cm venous aneurysm is visible (asterisk). B) Superselective angiography of the inferior alveolar artery better shows the venous aneurysm (asterisk).

Figure 5

Angiographic evaluation of the arterial supply through the inferior alveolar artery after releasing platinum GDC coils (arrow).

Figure 6

Angiographic evaluation of the facial artery. Another arterial supply to the arteriovenous malformation is visible by retrograde flow from two terminal branches of the submental artery, anastomosed with the mental artery (arrow).

Figure 7

Post-embolization angiographic evaluation of alveolar and submental arteries by external carotid common trunk catheterization. The AV malformation is completely occluded.