Intimal sarcomas of the aorta and iliofemoral arteries: a clinicopathological study of 26 cases.

Aortic sarcomas are predominantly endoluminal tumours that are believed derived from the intima. Because of their rarity, relatively little is known about their pathological features. We report a series of 26 aortic and iliofemoral tumours with histopathological and clinical data.Of the 26 cases, there were 16 men (63.6 ± 13 years) and 10 women (58.6 ± 18 years). Tumours occurred in the abdominal aorta (13), descending thoracic aorta (8), iliac or femoral arteries (4) and ascending aorta (1). Presenting tumour manifestations included claudication or peripheral vascular disease (6), pain (5), pulsatile aneurysm (2) abdominal aortic aneurysm (AAA; 2), occluded graft (2), renal artery stenosis (1), pain from bone metastasis (1), aortic rupture (1), fever (1), weight loss (1), vasculitis (1) impotence (1), incidental finding (1) and bowel ischaemia (1). The diagnosis was not suspected clinically in any case. The tumours were sampled by endarterectomy (9), aortic resection (8), repair of aneurysm (5), and in four the diagnosis was made at autopsy. Histologically and immunohistochemically, 13 were categorised as poorly differentiated angiosarcomas, seven as undifferentiated sarcomas, three as osteosarcomas, two as myxofibrosarcomas, and one as myxoid sarcoma, not otherwise specified. The undifferentiated sarcomas and angiosarcomas were histologically similar to one another and were characterised by tumour cells within and overlying thrombus. The angiosarcomas were defined by diffuse CD31 expression with co-expression of pancytokeratin in 10 (77%). Undifferentiated sarcomas were composed of spindled and/or epithelioid cells and 71% expressed smooth muscle actin. Histological material from metastatic tumours was available in two osteosarcomas and two undifferentiated sarcomas, and showed undifferentiated pleomorphic sarcoma in all cases.In this series, half of aortic intimal sarcomas are histologically undifferentiated and express endothelial and epithelial markers (epithelioid angiosarcoma). The second largest group is undifferentiated sarcoma without immunohistochemical evidence of endothelial differentiation and frequent actin positivity. Rare types include myxofibrosarcoma and osteosarcoma.