CLINICAL-SIGNIFICANCE OF THE COMET-TAIL ARTIFACT IN THYROID ULTRASOUND

The comet-tail artifact is commonly encountered in a variety of clinic al conditions; however, its presence and significance in a thyroid nod ule has not been documented before. We document its presence in 100 pa tients who underwent ultrasound examinations of the neck and thyroid. None of the thyroid nodules showed any evidence of malignancy on repea ted fine-needle aspiration cytology (FNAC). In 85% of patients with th e artifact, abundant colloid was seen on FNAC, suggesting that the art ifact may be related to the presence of colloid. Four different patter ns of distribution of the artifact within the nodule were noted and th ese helped to determine the size of the needle to be used for a succes sful aspiration. (C) 1996 John Wiley & Sons, Inc.