Anaplastic spindle-cell and giant-cell tumors of the thyroid gland

Abstract
Fifty‐three cases of anaplastic spindle‐cell and giant‐cell tumors of the thyroid gland were found in the files of the University of Michigan Medical Center in a 37‐year period (1932‐1969). Of these, 42 were found with other well‐differentiated thyroid carcinomas: papillary, follicular, Hürthle cell, clear cell, and medullary carcinomas. Data from this report and the recent literature support the conclusion that anaplastic tumors of the thyroid gland probably arise in preexisting well‐differentiated thyroid carcinomas. The grim prognosis for anaplastic carcinomas of the thyroid gland is reemphasized in this study; 49 of the 53 patients died within the first year after a histologic diagnosis was established.