High-grade neoplasms of the thyroid with an angiomatoid appearance by light microscopy have been debated for about 100 yr (1), and have not yet been included into the latest World Health Organization (WHO) classification of the thyroid (2). Several authors have described such tumors that display both anaplastic carcinoma and pseudoangiosarcomatous appearance, making difficult the inclusion of these tumors in either the anaplastic carcinoma of the thyroid or conventional angiosarcoma groups of the WHO classification. However, angiosarcoma generally represents a rare connective tissue tumor of the thyroid, and has been designated as malignant hemangioendothelioma by many authors (3, 4), and rarely occurs in that organ. We described a case of an angiosarcoma and well differentiated follicular carcinoma with intervening transitional area. The present report will provide an additional evidence that angiosarcoma of the thyroid is a specific condition of endothelial origin, which is different from angiosarcoma-like anaplastic carcinoma. Here, to confirm the nature of the present tumor, immunohistochemistry and ultrastructural examination were done.
CASE REPORTA 64-yr-old-man was admitted due to a painless mass in the anterior region of the neck that had been rapidly growing for several months. 99m Tc thyroid scan showed a cold defect in the right lobe of the thyroid. The results of thyroid function tests were within the normal ranges. He has a history of right pneumonectomy for tuberculosis about 20 yr ago. Fine needle aspiration cytology of the thyroid showed atypical cells showing nuclear pleomorphism and anaplasia, which were suggestive of anaplastic carcinoma. Careful examinations using radiologic methods as well as nuclear medicine did not disclose any metastatic or primary foci, and the tumor was confined within the thyroid region. The patient underwent total thyroidectomy. Two months later, slight dyspnea developed. Skull radiography showed multinodular osteolytic lesions and chest computed tomography showed multifocal bilateral scattered nodules, implying metastatic tumor nodules. He refused further evaluation. Chemotherapy and local radiation therapy were scheduled, but he was lost to follow-up.Grossly, the right lobe and left lobe measured 8×5×3 cm, and 6×3×2 cm. Each weighed 56 g and 20 g. The external
A Case of Coexistent Angiosarcoma and Follicular Carcinoma of the ThyroidAngiosarcoma of the thyroid has long been a controversial entity, and it is histologically defined as cleft-like anastosmosing spaces lined by large, atypical cells of endothelial lineage. However, clear-cut separation between the angiosarcoma and anaplastic carcinoma of the thyroid is difficult because they yield nearly the same clinical prognosis and overlapping histologic findings. We report a case of thyroid neoplasm composed of minimally invasive well differentiated follicular carcinoma and angiosarcoma with intervening transitional area. Immunohistochemically, the angiosarcomatous portion showed focal immunoreactivity for endotheli...