An aneurysm-like entity inside a giant carotid body tumor reaching lateral skull base

The successful resection of giant carotid body tumors (CBTs) with full protection of cranial nerve is challenging. Meanwhile, entities with fresh blood inside a CBT were commonly considered liquefactive necrosis preoperatively. However, we reported a case with an aneurysm-like entity inside the CBT instead. A patient with lump on the right neck complained of feeling dizzy. She was then reported with a giant CBT reaching lateral skull base. Preoperative imaging revealed a low-density entity inside the tumor, which was considered as liquefaction necrosis. However, during surgery, the low-density area was observed pulsing with fresh blood. Under the collaboration of vascular surgeons and otolaryngologists, the tumor was resected uneventfully. We reported a case of giant CBT over 10 cm and successful resection with no major facial nerve deficit. Moreover, an aneurysm-like entity inside the tumor was observed during the surgery, which was not reported before.