OBJECTIVETo evaluate the usefulness of ultrasonography in distinguishing follicular carcinoma from adenoma.

METHODSThe ultrasound data of 37 patients with histopathologically confirmed follicular carcinomas who were treated in PUMC Hospital from January 2000 to November 2012 were retrospectively studied. In addition, 74 sex-and age-matched patients with histopathologically confirmed adenomas during the same period were enrolled as the control group. The pathologic results were regarded as the gold standard.

RESULTSIrregular shape (32.4% of follicular carcinoma vs 5.4% of adenoma), absence of thin halo (67.6% vs 36.5%), indistinct margin (21.6% vs 1.4%), hypoechoic appearance (64.9% vs 39.2%), punctuate calcification(40.5% vs 13.5%), absence of cystic change (78.4% vs 54.1%), and being complicated with other thyroid disease (56.8% vs 28.4%) were more frequently associated with follicular carcinoma than with benign adenoma (P<0.05). No significant difference in the echotexture and internal flow was observed between the two groups (P>0.05).

CONCLUSIONAlthough follicular carcinoma and adenoma share many sonographic features, irregular shape, absence of thin halo, indistinct margin, hypoechoic appearance, punctuate calcification, absence of cystic change, and being complicated with other thyroid disease favor a follicular carcinoma diagnosis.