VWF and thyroid gland angiosarcoma: After total thyroidectomy and right cervical lymphadenectomy, postoperative histological examination revealed the presence of a thyroid angiosarcoma with positive staining for CD31 and for both Factor VIII-related antigen and Vimentin and only partially positive for staining pancytokeratin and presence of metastasis in cervical, supraclavicular, mediastinal and paratracheal lymph nodes.