Bilateral Carotid Aneurysms Secondary to Catastrophic Antiphospholipid Syndrome in a Patient with Differential Diagnosis of Polyarteritis Nodosa

Background: Extracranial Carotid Artery Aneurysm is considered a therapeutic and diagnostic challenge. In an unprecedented way in the literature, we describe an aneurysm originating from the Catastrophic Antiphospholipid Syndrome. Case Presentation: A 25-year-old male patient came to the Emergency Room of the ABC University Hospital in Sao Bernardo do Campo referring to bilateral neck pain for 1 month, associated with carotid aneurysms. Due to the severity and urgency of the clinical condition, immediate surgical therapy was performed without a definitive etiological diagnosis. The initial morphological analysis of the carotid artery suggested a diagnosis of Polyarteritis Nodosa. After anamnesis, physical examination, the use of a specific primary vasculitis algorithm, and a review of the pathological anatomy was requested, which showed bilateral carotid aneurysms secondary to catastrophic antiphospholipid syndrome. Conclusion: It remains evident that Extracranial Carotid Artery Aneurysm-related morbidity and mortality caused by Catastrophic Antiphospholipid Syndrome are influenced by a quick and correct diagnosis.