- Occur in 50% of population
- 93% are benign and only 7% are malignant
- Most common cause is benign thyroid hyperplasia
- Most specific USG sign is microcalcification; other specific signs are metastatic lymphadenopathy and adjacent organ invasion. Other USG signs of malignancy are marked hypoechotexture, AP dimesion more than trasverse, irregular illdefined margin, absence of hypoechoic halo
- On scintigraphy, a hot nodule is rarely malignant; 77% of cold nodules are benign
Hoang JK et al. US Features of Thyroid Malignancy: Pearls and Pitfalls. RadioGraphics 2007;27:847-860
