Primary epithelioid angiosarcoma of the thyroid: an infrequent malignant thyroid tumor.

We present a case of epithelioid angiosarcoma of the thyroid, a rare and aggressive tumor, in a 74-year-old woman with a chronic euthyroid goiter. The tumor, which involved most of the glandular surface of the thyroid, showed an infiltrating histological pattern, with epithelioid cells displaying a tendency to form vascular lights. Immunohistochemical analysis (CD31 and factor VIII) confirmed the angiomatous nature of the neoplasm and enabled us to establish the differential diagnosis with other malignant processes that can also affect this anatomical area.