Like the name suggests, this disease occurs without pain. Painless thyroiditis is a disease in which inflammation of the thyroid gland occurs, and thyroid hormones stored in the gland leak into the blood. This leads to a temporary excess of thyroid hormones, but the condition subsequently resolves itself. When hormone levels are high, symptoms similar to those of Basedow’s disease may appear. Usually, painless thyroiditis resolves without treatment in 1-4 months.
Acute exacerbation of Hashimoto’s disease is rare. Pain in the thyroid and fever occur, and thyroid function may decline relatively rapidly while symptoms disappear and reappear. The disease is treated with analgesics or steroid hormones, but the symptoms may occur repeatedly. If it is difficult to discontinue drug therapy, then surgery may be performed.
In Hashimoto’s disease, chronic inflammation of the thyroid occurs and lymphocytes invade the gland. Normally, there is no lymphoid tissue in the thyroid. In this disease, the lymphocytes transform into cancerous cells and cause malignant lymphoma. In patients with malignant lymphoma of the thyroid, approximately 90% have Hashimoto’s disease, showing a clear association. However, only a small proportion of patients with Hashimoto’s disease develop this form of cancer. Overall, lymphoma developing directly from the thyroid is very rare. It accounts for only 1-2% of all malignant lymphomas and 2-5% of malignant tumors of the thyroid gland.