Toxic Nodular Goiter simply means that your thyroid is enlarged. And it contains growths called nodules. In addition, your thyroid gland is producing too much thyroid hormone. Hence, the term Toxic. In other words, you have an enlarged thyroid gland with multiple nodules in it. Toxic simply means that the goiter – enlarged thyroid gland – is giving rise to hyperthyroidism. Rarely, there may be a single nodule instead of multiple ones.
Symptoms of Toxic Nodular Goiter
Symptoms of hyperthyroidism in a toxic nodular goiter are usually minimal. In addition, symptoms may be unusual especially in the elderly. For example, the only symptom may be a new onset of atrial fibrillation or congestive heart failure.
Rarely, a multi-nodular goiter may cause some pressure symptoms, such as compression on the trachea, difficulty swallowing or hoarseness of voice.
Diagnosis of Toxic Nodular Goiter
Diagnosis is based on the clinical findings of a nodular goiter and a low TSH on thyroid function test. Free T3 and Free T4 may be normal or elevated.
The next step is to do a Radioiodine uptake and scan to confirm the hyper-functioning status of these nodules. Any overactive nodule manifests as a hot nodule on the scan. What is a hot nodule? When a nodule takes up more radioiodine than the uptake by the rest of the gland. Hot nodules are almost never malignant.
An Ultrasound of the thyroid should also be done to evaluate the size and other features of the nodules. Usually, a multi-nodular gland with hyperthyroidism is non-malignant. However, if there is a large nodule, or if a nodule starts to enlarge or has suspicious features on an ultrasound, your endocrinologist will likley recommend an ultrasound-guided Fine Needle Aspiration (FNA) biopsy to exclude malignancy.
Difference Between Toxic Nodular Goiter and Graves’ Disease
Patients with Graves’ Disease usually have a goiter as well, but this goiter is typically diffuse. Hence, the term Toxic Diffuse Goiter, which is another name for Graves’ Disease.
In case of a Toxic Nodular Goiter, usually a person has a visible goiter for a number of years, but their thyroid function is normal. Then, hyperthyroidism develops gradually. This is in sharp contrast to Graves’ Disease, where hyperthyroidism develops rapidly and the goiter is diffuse, not nodular.
However, rarely a nodule may be present in the thyroid gland of a Graves’ Disease patient. It may carry a higher than normal risk of malignancy. Your endocrinologist will likely recommend an ultrasound-guided Fine Needle Aspiration (FNA) biopsy to exclude thyroid cancer in such cases.
Treatment of Toxic nodular goiter is with surgery. Occasionally, radioactive iodine is employed in an elderly patient, whose overall health may be too poor to undergo surgery.