Keywords
aortic sarcoma - distal embolization - imaging - surgical resection - adjuvant therapy
Discussion
Primary aortic sarcomas are a very rare condition which carries a dismal prognosis.[1] They include leiomyosarcoma, fibrosarcoma, angiosarcoma, hemangioendothelioma, and myxoid sarcoma.[1] They are more commonly localized in the abdominal aorta and they arise from the aortic media or the intima, with the latter being the most common.[2] Among aortic sarcomas, myxoid type is almost a unique finding.[3] Intimal sarcomas typically present with symptoms of distal embolization, whereas sarcomas arising from the media have an even subtler presentation.[2]
The challenge of establishing a correct diagnosis in cases presenting with distal embolization relies on the implementation of an algorithm aimed at identifying the source of embolization and defining the nature of the primary pathology. Once the heart is ruled out as the primary possible embolization site with transesophageal echocardiogram, evaluation of the aorta by computed tomography scan or magnetic resonance imaging is required,[4]
[5] since a primary pathology of the aorta such as an intraluminal wall thrombus and an infectious or neoplastic process can represent the embolic source. Differential diagnosis includes, in absence of aneurysmal disease or severe atherosclerosis of the aorta, idiopathic thoracic aortic thrombosis, aortitis, and a neoplastic or infectious process.[4]
Diagnosis is obtained by microscopic examination of the secondary embolization site and by pathology examination of the primary aortic specimen.
Indication for aortic replacement is represented by any floating aortic mass associated with distal embolization.[4]
[5] Also, the need to obtain a tissue diagnosis may indicate surgery. In the case presented, the choice for left carotid artery cannulation as inflow for cardiopulmonary bypass with deep hypothermic circulatory arrest was dictated by the need to avoid retrograde aortic flow and aortic cross-clamping to minimize the risk of cerebrovascular embolization.
In cases of aortic sarcoma, aortic replacement with adjuvant therapy offers the best palliation. Longer survival is achieved for differentiated tumors but surgery may be futile in cases with high tumor grade and diffuse metastatic spread.[3]
