RESUMEN
<p><b>OBJECTIVE</b>To explore the difference of the ultrasonic features between anaplastic thyroid carcinoma and papillary thyroid carcinoma.</p><p><b>METHODS</b>The ultrasound data of 7 patients with histopathologically confirmed anaplastic thyroid carcinomas who were treated in PUMC Hospital from April 2001 to June 2014 were retrospectively studied. In addition, 21 sex-and age-matched patients with histopathologically confirmed papillary thyroid carcinomas during the same period were enrolled as the control group. The pathologic results were regarded as the gold standard. The ultrasonic features of anaplastic thyroid carcinoma and papillary thyroid carcinoma were analyzed and compared.</p><p><b>RESULTS</b>Patients with anaplastic thyroid carcinoma were predominantly females (5/7,71.4%), with an average age of (64.9 ± 11.3) years. Large mass [(5.17 ± 1.26) cm vs. (1.85 ± 1.89)cm, P<0.001], anteroposterior-to-transverse diameter ratio less than 1(100.0% vs. 47.6%, P ＝ 0.03), and punctuate calcification (100.0% vs. 52.4%, P ＝ 0.03) were more frequently associated with anaplastic thyroid carcinoma than with papillary thyroid carcinoma. No significant difference was observed between the two groups in the shape, margin, cystic change, echogenicity, echotexture,vascularity,and envelope (all P>0.05).</p><p><b>CONCLUSION</b>In elderly women with common malignant features on ultrasound, the thyroid nodules with a maximum diameter greater than 5 cm,anteroposterior-to-transverse diameter ratio less than 1,and microcalcifications are highly likely to be anaplastic thyroid carcinoma.</p>