A cold nodule on thyroid scintigraphy is indicative of a lesion with decreased or absent function in regards to the uptake and trapping of iodine. It carries an estimated 10-20% risk of malignancy and hence is typically further assessed by thyroid ultrasound. If the US does not show clearly benign features (such as an anechoic colloid cyst) tissue sampling is often pursued (as in this case)
Once acronym for the differential diagnosis of a cold nodule on thyroid scintigraphy is CATCH PALM and stands for: