Pseudoaneurysm of the facial artery after the injection of local anesthetics.

Generally, a true aneurysm is a dilatation of the vessel wall, whereas a pseudoaneurysm (PA) is a weakening or rent in a vessel wall, with contained rupture into the surrounding tissues. In the face, PAs of the facial artery are an extremely rare development after penetrating or blunt trauma. A 31-year-old woman presented with nontender, palpable, and firm lump that had been steadily increasing in size over a 4-week period. Examination confirmed a firm and spherical swelling in the left mandibular area, which was nonpulsatile. The patient presented with a mass on the upper part of her left chin 6 months after the injection of local anesthetics for dental treatment. After the procedure, a hematoma developed over the injection site, and it was treated with local ice. This case is unique in that the lesion seen using computed tomography and ultrasonography scanning had an unusual presentation. Ultrasonography revealed thrombi within the tumor, and color Doppler examination showed blood moving in the perivascular mass. During the operation via intraoral incision, a lesion was found as a dilation of the muscular branch of the facial artery. The facial artery was exposed, isolated, and tied off with a 2-0 white silk ligature. Histopathologic analysis determined that the content of the fragile cystic lesion was an organized thrombus and hematoma. As with any penetrating facial injury, local anesthetics can damage vessels and produce a PA. Therefore, we present a rare case of false facial artery aneurysm with no associated risk factors, which was nonpulsatile on presentation.