Which thyroid nodule are cancerous i am hypo with one small nodule 2 cm or mm don't know what should i do taking 25mcg levothyroxin plz ans in detail ?

Size & US appearance: Size of thyroid nodules is important. Usually larger than 1-1.5 cm. goes for fine needle biopsy. Certain ultrasound characteristic such as predominantly cystic, surrounding halo, avascular appearances usually benign lesion.Microcalcifications, marked hypoechogenicity, exttraglandular extension, abnormal regional lymph nodes, absent or irregular halo, and solid composition- usually malignant.