Epithelioid angiosarcoma of the thyroid. Clinicopathological analysis of seven cases from non-Alpine areas.

Epithelioid angiosarcomas of the thyroid usually develop in people living in Alpine regions, and only rare cases arising in subjects living in nonmountainous areas have been reported. We describe the clinicopathological features of a series of seven cases collected from non-Alpine areas. All patients were adults. The tumours appeared as haemorrhagic, unencapsulated, sometimes cystic nodules. In two cases multinodularity was present. They were composed of large, epithelioid cells, which lined vascular-like spaces or were arranged in solid sheets. Intracytoplasmic lumina containing red blood cells were identified. Neoplastic cells were diffusely positive for factor VIII-related antigen, Ulex europaeus agglutinin, CD31 and keratin peptides. Ultrastructural studies were performed in four cases and showed features of endothelial differentiation. An average follow-up of 3.8 years disclosed that four patients died of disease after a median survival time of 5 months, whereas 3 patients are still alive with no evidence or residual disease 27, 32 and 66 months after thyroidectomy. The good prognosis in these patients appears to be related mainly to the absence of extraglandular tumour spread at the time of surgery.