Also peripheral flow is also an indicator of benign nodules, it is internal flow that is worrisome. Also the lack of microcalcifications is a good thing, microcalcifications are the single largest indicator of malignancy in thyroid nodules.
A complex mass means that there is both cystic and solid component parts of the nodule. Hypoechoic is the appearance under US and really is not an accurate indicator of malignant versus benign nodules. Spongiform appearance is usually an indicator for a benign colloid nodule. What are the size of the nodule(s) that were noticed on US? Size and risk factors will determine if you will need biopsy.
I have a complex nodule that is 1.7 cm. I had a FNAB and it came back as a benign colloid nodule. I know this can be very worrisome, just try to keep things in perspective and don't worry until you have something to worry about.
Thyroid nodules are very common and the vast majority are benign. Even it is malignant, treatment and prognosis is excellent with minimal effects.
Jetmech