Extracranial internal carotid artery mycotic aneurysm: case report and review.

Mycotic aneurysms of the internal carotid artery (ICA) are rare and often difficult to diagnose. They can have nonspecific signs and symptoms, an unclear etiology, and can lead to severe morbidity and mortality if left untreated. We present a case of a 47-year-old woman with an apparent mycotic aneurysm of the extracranial ICA associated with Klebsiella pneumonia. We discuss the various clinical findings and radiographic imaging that lead to this unusual diagnosis and the details of our surgical treatment, which included excision of the mycotic aneurysm and reconstruction with a greater saphenous vein interposition graft. We also review the literature on mycotic aneurysms of the ICA, including the radiologic modalities available to diagnose this condition, epidemiology, pathophysiology, and treatment options.