Angiosarcoma of the thyroid and concurrent hyperthyroidism.

We describe the exceptional association of an angiosarcoma of the thyroid and hyperthyroidism in a 74-year-old woman who presented with a toxic multinodular goiter of recent growth. This association reported in two other cases may not be fortuitous but due a vascular effect of the angiosarcoma contributing to the development of thyrotoxicosis. This case also illustrates the diagnostic difficulties and the poor prognosis of this tumor.