From the Guidelines
Toxic multinodular goiter is a condition where the thyroid gland becomes enlarged with multiple nodules that produce excess thyroid hormones independently of normal regulatory mechanisms. This disorder typically develops gradually from a non-toxic multinodular goiter, often occurring in people with long-standing goiters, particularly middle-aged and elderly individuals 1. Patients experience hyperthyroidism symptoms including weight loss, increased appetite, heat intolerance, sweating, anxiety, tremors, palpitations, and sometimes atrial fibrillation. Unlike Graves' disease, eye problems are uncommon.
Diagnosis and Treatment
Diagnosis involves thyroid function tests showing elevated T3 and T4 with suppressed TSH, along with imaging studies like ultrasound or radioiodine scans showing multiple functioning nodules 1. Treatment options include:
- Anti-thyroid medications (methimazole 5-30 mg daily or propylthiouracil 100-300 mg daily)
- Radioactive iodine therapy to destroy overactive tissue
- Surgery (total or subtotal thyroidectomy) Beta-blockers like propranolol (20-40 mg three times daily) may be used temporarily to control symptoms.
Pathophysiology
The condition differs from Graves' disease in its pathophysiology, as it results from autonomous nodular growth rather than autoimmune stimulation of the thyroid gland, and tends to be permanent without definitive treatment 1. According to the ACR Appropriateness Criteria, imaging has a key role in diagnosing and characterizing the thyroid finding for management 1.
From the FDA Drug Label
In patients with Graves’ disease with hyperthyroidism or toxic multinodular goiter for whom surgery or radioactive iodine therapy is not an appropriate treatment option. Propylthiouracil is a prescription medicine used to treat people who have Graves’ disease with hyperthyroidism or toxic multinodular goiter.
Toxic multinodular goiter is a condition that is treated with medications such as methimazole 2 and propylthiouracil 3 3. It is associated with hyperthyroidism and is an indication for the use of these medications when surgery or radioactive iodine therapy is not appropriate. The exact definition of toxic multinodular goiter is not provided in the drug labels, but it is mentioned as a condition that can be treated with these medications.
From the Research
Definition and Overview
- Toxic multinodular goiter (TMNG), also known as Plummer's disease, is a condition where the thyroid gland becomes enlarged and develops multiple nodules, leading to an overproduction of thyroid hormones 4.
- This condition is characterized by the presence of multiple nodules in the thyroid gland, which can cause hyperthyroidism, a condition where the thyroid gland produces excess thyroid hormones 5.
- TMNG is more common in older adults and is often associated with a long-standing goiter, which is an enlargement of the thyroid gland 6.
Causes and Risk Factors
- The exact cause of TMNG is not fully understood, but it is thought to be related to the aging process and the formation of nodules in the thyroid gland 6.
- Risk factors for developing TMNG include a family history of thyroid disease, radiation exposure, and certain medical conditions such as Graves' disease 5.
Symptoms and Diagnosis
- Symptoms of TMNG can include weight loss, palpitations, tremors, and heat intolerance, among others 5.
- Diagnosis is typically made through a combination of physical examination, laboratory tests, and imaging studies such as ultrasound or radioactive iodine scan 4.
Treatment Options
- Treatment options for TMNG include antithyroid medications, radioactive iodine ablation, and surgical thyroidectomy 4, 5.
- The choice of treatment depends on the severity of the condition, the presence of any underlying medical conditions, and the patient's preferences 4.
- Long-term methimazole treatment has been shown to be a safe and effective option for managing TMNG, with some studies suggesting it may be superior to radioactive iodine treatment in terms of achieving and maintaining euthyroidism 7, 8.