Thyroid cancers are an endocrine system cancer, so you are right it is different. But having said that, I and others here have had nodules develop post treatment around our thyroids, and we haven't had anyone post here that there was anything serious, always benign. Related to the waiting for it to get larger to biopsy, mine never did. They are still there 6 years later, no bigger, except one that was taken out while a different procedure was being done and it was a benign nodule.

Factoids you may or may not know. Nodules like these are the most common endocrine system abnormal finding to give you an idea how common they are.

One in 12 to 15 young women has a thyroid nodule.
One in 40 young men has a thyroid nodule.
More than 95% of all thyroid nodules are benign (non-cancerous growths).
Some are actually cysts, which are filled with fluid rather than thyroid tissue.
Most people will develop a thyroid nodule by the time they are 50 years old.
The incidence of thyroid nodules increases with age.
50% of 50 year olds will have at least one thyroid nodule.
60% of 60 year olds will have at least one thyroid nodule.
70% of 70 year olds will have at least one thyroid nodule.

Since you did not have radiation this fact is of no importance to you, but I put it here for others.

People that have had high dose radiation are at risk for thyroid cancer, but the occurrence of it is usually a couple decades after radiation exposure. ( We all hope to live that long right?) When found early (yours would certainly fall into that category if it even is a bad guy) virtually all thyroid cancers are curable and survivable.

One question I would like to ask is if you "felt this" or if your discovered it/them because you have symptoms of hyperthyroidism?