Fig. 3

Histopathological examination of surgical specimens. Low-power view of the anaplastic thyroid carcinoma (ATC) component (a). Inflammatory granulation tissue is observed on the left side, whereas highly atypical squamoid ATC cells are still remaining on the right. The granulation tissue contains many small spindle cells with degenerative pyknotic nuclei (b) which are distinctly positive for cytokeratin AE1/AE3 (c). High-power view of the viable ATC cells (d). Papillary thyroid carcinoma is observed on the periphery of the ATC (e).