Borders of the nodule
Benign hyperplastic nodules - Case 17

In most cases a hyperplastic nodule displays a sharp, regular border and has a regular oval shape.
 
Benign hyperplastic nodules - Case 20

The borders of this nodule is irregular, sharp, puzzle-like. Such pattern is frequently observed in Hashimoto's thyroiditis. Moreover, the taller than wide sign can be observed, as well.
   
Benign hyperplastic nodules - Case 43

The borders of the above nodule are blurred, ill-defined. This pattern is a specific sign both of de Quervain's thyroiditis and of papillary cancer.
mask