Thyroid Nodule Evaluation in San Diego
What thyroid nodules are, how we decide which ones need a biopsy, and what happens next.
Thyroid nodules are very common. With ultrasound, they can be found in up to half of adults by age 60, and most never cause harm. The purpose of an evaluation is to answer two questions: is this nodule cancer, and does it need any treatment at all?
At Diabetes & Endocrine Specialists, the endocrinologist who sees you also performs the ultrasound and, when needed, the biopsy. That keeps the evaluation in one place, usually over one or two visits, and avoids biopsies that are not needed.
What a thyroid nodule is
A nodule is a lump of thyroid cells that grows differently from the rest of the gland. Nodules are often found by chance, on a CT or MRI done for another reason, on a carotid ultrasound, or when a doctor feels the neck during a routine exam. Some people notice a lump themselves.
Nodules can be solid, filled with fluid (cystic), or a mix of both. Purely cystic nodules are almost always benign. Solid nodules carry a higher, but still small, chance of cancer. A gland with several nodules is called a multinodular goiter.
How likely is cancer?
Roughly 5 to 15 percent of thyroid nodules are cancerous, and most thyroid cancers found this way are slow-growing and highly treatable. The risk for an individual nodule depends mainly on how it looks on ultrasound, which is why a good ultrasound matters more than nodule size alone.
Symptoms
Most nodules cause no symptoms. When they do, it is usually because of size or hormone production:
- A visible lump or a feeling of pressure in the neck
- Difficulty swallowing, or a sense of something stuck in the throat
- Discomfort when lying flat or wearing a tie or necklace
- Hoarseness, which should always be evaluated
- Palpitations, weight loss, heat intolerance or anxiety, if a nodule makes too much thyroid hormone
How we evaluate a nodule
1. Blood tests
We start with TSH. If TSH is low, the nodule may be producing thyroid hormone (a “hot” nodule). Hot nodules are rarely cancerous and are evaluated with a thyroid uptake scan rather than a biopsy.
2. Thyroid ultrasound
Dr. Schneider, who holds the Endocrine Certification in Neck Ultrasound (ECNU), performs the ultrasound in our office. We look at each nodule’s composition, echogenicity, shape, margins and calcifications, and at the lymph nodes in the neck, and assign a risk category using the ACR TI-RADS system. More about thyroid ultrasound.
3. Biopsy, only when it is indicated
Whether a nodule needs a biopsy depends on its ultrasound category and size. Higher-risk nodules are usually biopsied once they reach about 1 cm; low-risk nodules only when larger; and purely cystic nodules generally not at all. When a biopsy is needed, we perform an ultrasound-guided fine-needle aspiration (FNA) in the office.
| Biopsy result (Bethesda) | What it usually means |
|---|---|
| Benign | Follow with ultrasound; treat only if it grows or causes symptoms |
| Indeterminate | Molecular testing of the sample, a repeat biopsy, or surgery, depending on the result and your preferences |
| Suspicious or malignant | Referral to an experienced thyroid surgeon |
| Non-diagnostic | Repeat biopsy, usually after a few months |
Follow-up
Nodules that do not need a biopsy, and nodules with a benign biopsy, are usually rechecked with ultrasound at intervals of one to several years, depending on their appearance. Bringing prior ultrasound reports and images to your visit lets us measure growth accurately.
Treatment, if it is needed
Most benign nodules need no treatment. Treatment is considered when a benign nodule grows, causes pressure, swallowing difficulty or a visible lump, keeps refilling with fluid, or makes too much thyroid hormone. Options include observation, thyroid radiofrequency ablation (RFA), ethanol ablation for cysts, radioactive iodine for hot nodules, and surgery. See thyroid nodule treatment options.
Our physicians perform thyroid RFA in the office and have reported six-month outcomes in 118 consecutive patients, presented as an oral presentation at ENDO 2026. Details on the procedure are at San Diego Interventional Endocrinology.
Common questions
Can a nodule turn into cancer?
A benign nodule very rarely becomes cancerous. Follow-up ultrasound is mainly to watch for growth or a change in appearance.
Can thyroid nodules go away on their own?
Cystic nodules can shrink or disappear. Solid nodules usually stay the same or grow slowly.
Do nodules affect thyroid hormone levels?
Usually not. Most people with nodules have normal thyroid function. A minority of nodules make extra hormone, and some people also have Hashimoto’s thyroiditis.
Do I need a referral?
Many insurance plans require one. Your physician can refer you through our referral page.
Have a nodule evaluated
Thyroid ultrasound and biopsy are performed at our La Jolla office. Call (858) 622-7200 or send a request.
Sources: Haugen BR, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016;26:1–133. Tessler FN, et al. ACR Thyroid Imaging, Reporting and Data System (TI-RADS). J Am Coll Radiol. 2017;14:587–595. Ali SZ, et al. The 2023 Bethesda System for Reporting Thyroid Cytopathology. Thyroid. 2023;33:1039–1044. Written by Darius A. Schneider, MD, PhD. Reviewed October 2026.
