A misdiagnosed aneurysm of the petrous internal carotid artery: A case report

INTRODUCTION: An aneurysm is characterized by the weakening of the arterial wall, which leads to a bulge that can be filled with blood. Aneurysms of the petrous portion of the internal carotid artery are rare and predominantly detected incidentally. This is a report of multiple misdiagnoses of an aneurysm of the petrous segment of the internal carotid artery (ICA) that highlights its imaging-based diagnosis and risk of mortality. PRESENTATION OF CASE: A 60-year-old woman with chronic kidney disease and a history of stroke presented with left ear discharge, decreased hearing, and non-pulsatile tinnitus that had persisted for four months. Clinical examination showed wet tympanic membrane perforation, and imaging revealed an ill-defined infiltrative mass involving the left petrous apex initially misdiagnosed as glomus jugulare. Diagnostic computed tomography (CT) angiography revealed a left aneurysm in the petrous part of the ICA, which was successfully treated with interventional radiology. Follow-up was planned for infectious diseases and internal medicine, but she was lost to follow-up by the otolaryngology department. DISCUSSION: Aneurysms in the petrous portion of the ICA are rare and usually asymptomatic. However, their clinical manifestations vary, and they have various differential diagnoses. CT and magnetic resonance imaging are essential for diagnosis, and CT angiography is the gold standard. CONCLUSION: Diagnosing petrous ICA aneurysms requires a high level of suspicion and CT angiography. Their clinical presentations vary from asymptomatic to severe. Case-specific management and endovascular treatment yield positive neurological outcomes.