Conditions: Chronic Lymphocytic Thyroiditis (also known as Hashimoto’s Thyroiditis )

What is chronic lymphocytic thyroiditis (Hashimoto’s thyroiditis)?

Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, is an autoimmune disorder that affects the thyroid gland. Hashimoto’s thyroiditis eventually causes hypothyroidism, and overall Hashimoto’s is the most common cause of hypothyroidism. At its onset, however, it might cause a brief period of hyperthyroidism before thyroid hormone output begins its slow and progressive decline. Hashimoto's occurs when the immune system mistakenly attacks the thyroid tissue, leading to inflammation and damage over time. This chronic condition primarily affects women and tends to run in families. Diagnosis is typically made through blood tests that measure thyroid hormone levels and detect specific antibodies. Although there is no cure for Hashimoto's, it can be effectively managed with medications that replace the missing thyroid hormones. Regular monitoring and medication adjustments are necessary to maintain hormonal balance and alleviate symptoms.

How common is Hashimoto’s thyroiditis?

The new development of Hashimoto’s thyroiditis happens in approximately three to six people per 10,000 population per year. The prevalence of Hashimoto’s thyroiditis in the overall population is at least 2%.

How is Hashimoto’s thyroiditis diagnosed?

Hashimoto’s thyroiditis may be associated with a goiter or a normal sized thyroid. Therefore, thyroid size is not especially useful in making this diagnosis, though it may increase diagnostic suspicion. Hashimoto’s is typically painless, which is in contrast with a similar but painful condition called chronic granulomatous thyroiditis.

Hashimoto’s thyroiditis is usually diagnosed with bloodwork. The decision to obtain this bloodwork is typically made when a young woman is found to have a diffuse, smooth, firm goiter. Results supportive of Hashimoto’s include strongly positive titers of antibodies against thyroglobulin (TG Ab) and/or thyroid peroxidase* (TPO Ab) and a euthyroid or hypothyroid metabolic state. (Note: Young patients with even low levels of these antibodies are considered positive.) A patient with antibodies to thyroglobulin and thyroid peroxidase but without hypothyroidism or a goiter is considered to have “suspected” Hashimoto’s disease.

Ultrasound guided fine needle aspiration biopsy usually demonstrates findings of Hashimoto’s, when the disease is present. USGFNAB is typically not necessary to make the diagnosis of Hashimoto’s thyroiditis, but may be indicated for the evaluation of a suspicious thyroid nodule. More recently, the images from an ultrasound have been found to be helpful in suggesting the diagnosis of Hashimoto’s.

Radioiodine uptake scanning is not always needed for the diagnosis of Hashimoto’s thyroiditis, but can be helpful. The image is characteristically that of a diffuse or mottled uptake in a goiter, in striking contrast to the focal "cold" and "hot" areas of multinodular goiter. Areas of severely disease thyroid replaced with scar will lack uptake of radioiodine.

* Antimicrosomal antibody is a synonym for anti-thyroid peroxidase antibody.

How is Hashimoto’s thyroiditis treated?

Not all Hashimoto’s requires treatment. A patient with a small goiter and euthyroidism, for example, does not require therapy unless the TSH level is elevated. The presence of a very large or progressively growing gland or hypothyroidism indicates the need for replacement thyroid hormone. Surgery is rarely indicated for Hashimoto’s disease alone. Development of lymphoma, though rare, may be considered if there is nodular growth or pain in the involved gland.