What to Know About Thyroid Lymphoma

Thyroid lymphoma is an extremely rare but highly treatable cancer that affects the thyroid gland. It can cause a mass in the neck, difficulty swallowing, and shortness of breath.

Most cases of thyroid cancer start when thyroid gland cells become cancerous.

Thyroid lymphoma, meanwhile, is a disease that happens when lymphocytes, or white blood cells that fight infection, become cancerous in the thyroid gland.

It’s essentially a combination of lymphoma (a cancer affecting white blood cells or immune cells) and thyroid cancer. Fortunately, it’s very treatable and has a fairly positive outlook.

Here’s what to know about its diagnosis, outlook, and treatment.

What is thyroid lymphoma?

Thyroid lymphoma is very rare, affecting an estimated 2 in 1 million individuals worldwide. It makes up less than 5% of all thyroid malignancies and less than 3% of extranodal (lymphomas that occur outside of the lymph nodes) each year.

The two main types of thyroid lymphomas include:

• Primary thyroid lymphoma: This affects the thyroid gland first, and then spreads to the lymph nodes and other organs.
• Secondary thyroid lymphoma: This affects the lymph nodes and other organs first, then spreads to the thyroid.

Symptoms of thyroid lymphoma

Unlike many other types of thyroid cancer, thyroid lymphoma often causes noticeable symptoms, including :

• a firm mass or goiter in the neck that grows quickly and can easily be felt or seen
• issues with swallowing or a sensation that food is getting stuck in the throat
• shortness of breath or pressure, especially when lying on the back
• voice hoarseness

Those with the condition may experience thyroid-related symptoms like:

• weight loss
• fever
• night sweats
• itchiness
• fatigue
• constipation
• cold intolerance
• dry skin/hair
• menstruation irregularities

While most thyroid cancers don’t cause symptoms, thyroid lymphoma tends to grow very quickly and be noticed more quickly than other types.

Diagnosis

According to a 2024 review , thyroid lymphoma symptoms may occur anywhere from a few days to a few years before a formal diagnosis, but it usually occurs on the shorter end of the spectrum.

Diagnosing thyroid lymphoma may include:

• Physical exam: Your doctor may check for a goiter or mass.
• Imaging tests: Tests like an ultrasound to view any affected cells. These may be followed by CT, MRI, or PET scans.
• Biopsy: A doctor will test the sample of atypical cells to confirm a definitive diagnosis.
• Laboratory tests: Blood tests to assess the thyroid function and check for markers of thyroid autoimmune diseases.

Since thyroid lymphoma may be confused with other more aggressive forms of cancer, such as anaplastic thyroid cancer , a prompt diagnosis is advisable.

Survival rate

According to the same 2024 review mentioned previously, the survival rate for thyroid lymphoma with clinical treatment is generally very good. The 5-year disease-free survival rates range from 75% to 96%, depending on the type of thyroid lymphoma, including:

• 96% for mucosa-associated lymphoid tissue (MALT) lymphoma, or a type of thyroid lymphoma that develops in mucous membranes
• 87% for follicular lymphoma, which develops in the follicles of the lymph nodes in the thyroid
• 86% for small lymphocytic lymphoma, which is a slow-growing type of lymphoma that affects B-lymphocyte blood cells in particular
• 75% for diffuse large B-cell lymphoma, a fast-growing type of lymphoma that affects B-lymphocyte blood cells in particular

Causes and risk factors

Though the exact cause of thyroid lymphoma remains unknown, a few risk factors to know about include :

• Hashimoto’s thyroiditis: People with this autoimmune condition are significantly more likely to develop thyroid lymphoma.
• Age: People over 60 years are much more likely to get it.
• Gender: Women are much more likely to develop it than men.
• Iodine intake: Low iodine may be a risk factor for thyroid cancer in general, but more research is necessary to know for sure.

Treatment

Since it’s a localized disease that’s often caught in its early stages, thyroid lymphoma generally responds well to treatment. Management includes:

• Chemotherapy: This is the primary treatment for most cases and is highly effective. In some cases, people may see extreme improvements within days.
• Radiation therapy: This is sometimes used in combination with chemotherapy or on its own.
• Surgery: While it isn’t often used, it may be necessary to form a proper diagnosis or to mitigate airway obstruction.

The bottom line

Thyroid lymphoma is a rare but serious form of cancer. Fortunately, it’s highly treatable and has a positive 5-year outlook.

If you notice any sudden changes in your throat, such as a lump, or experience symptoms like difficulty swallowing or breathing, it’s a good idea to contact a doctor.