What is primary thyroid lymphoma?

Primary thyroid lymphoma (PTL) is a rare type of thyroid cancer. It arises from special blood cells called lymphocytes. PTL accounts for 1 to 5% of all thyroid cancers, 1 to 2% of all lymphomas outside of lymph nodes, and has an annual incidence of 2 cases per one million people. There are several different kinds of lymphoma, but the vast majority of patients are diagnosed with non-Hodgkin's lymphoma (NHL). Determining the exact type of the lymphoma is important for treatment choice and prognosis.

Lymphoma is a disease in which lymphocytes (i.e. blood cells that fight infection) turn into cancer cells. In thyroid lymphoma, the lymphocytes of the thyroid turn into cancer cells. Thyroid lymphoma is a very rare disease that accounts for 1 to 2% of all thyroid cancers and 1 to 2% of all lymphomas outside the lymph nodes. Most patients are older with an average age in the late 60's. If properly diagnosed and treated, the prognosis is very good.