Neck dissection complicated with congenital internal carotid artery hypoplasia: A case report

Preoperative diagnosis of the presence of anomalies or abnormalities of the cervical vessels is important to safely perform neck dissection in patients with head and neck cancer. We present a case of cervical lymph node metastasis from carcinoma of unknown primary origin in a 72-year-old man. The patient had a huge lymph node metastasis in his right neck that was more than 90° adjacent to the common carotid artery. Imaging studies incidentally revealed right internal carotid artery hypoplasia. Internal carotid artery hypoplasia is a very rare vascular anomaly with an incidence of <0.01%. Previous reports have focused on the imaging findings and have not shown the macroscopic findings of a cervical hypoplastic internal carotid artery in a living patient. Intraoperative findings of the neck dissection in the present case showed that the hypoplastic internal carotid artery branched from the common carotid artery as a cord thinner than the vagus nerve, and no pulsation was observed. This is the first report of neck dissection in a patient complicated with internal carotid artery hypoplasia. Although this is a very rare condition, it is a vascular anomaly that should be considered by head and neck surgeons who routinely perform operations around the carotid artery