Squamous cell carcinoma (SCC) of the thyroid is thought to be rare. Ho
wever, SCC not infrequently occurs in conjunction with other histologi
c types of tumor. We reviewed 67 thyroid cancer autopsy cases obtained
from two institutions from 1969 to 1981 and from 1975 to 1992, respec
tively. SCC was found in 19 cases (28.4%): 2 SCCs as the only malignan
cy and of uniform histologic type, 9 cases of tumors mixed with papill
ary carcinoma, and 8 cases of SCC mixed with papillary and anaplastic
carcinomas. In only four of these cases was the SCC component found in
the surgical specimens. These results indicate that the presence of S
CC component is more likely to be found at the later stage of the dise
ase.