Solitary thyroid nodules. Separating benign from malignant conditions.

Although features found on history taking, physical examination, thyroid function tests, and imaging studies help categorize solitary thyroid nodules as benign or malignant, fine-needle aspiration biopsy is the diagnostic test of choice. Nodules found to be malignant on cytologic examination should be treated with surgery. Benign nodules may be followed clinically or treated with levothyroxine to suppress their growth. Intermediate nodules should be excised if there is clinical suspicion of malignancy. In suspect nodules, levothyroxine therapy with follow-up ultrasound assessment for size is appropriate. Nodules that do not shrink significantly within 6 months should be excised.