Hurthle cell cancer doesn't always cause symptoms, and it's sometimes detected during a physical examination or an imaging test done for some other reason.

Signs and symptoms of Hurthle cell cancer may include:

• A lump in your neck, just below your Adam's apple
• Pain in your neck or throat
• Hoarseness or other changes in your voice
• Shortness of breath
• Swallowing difficulty

These signs and symptoms don't necessarily mean you have Hurthle cell cancer. They may be indications of other medical conditions — such as inflammation of the thyroid gland or a noncancerous enlargement of the thyroid (goiter).

It's not clear what causes Hurthle cell cancer.

Doctors know that cancer begins when a cell develops errors in its DNA — the genetic material that contains instructions for biochemical processes in your body. When DNA is altered or damaged, these genes may not function properly, causing cells to grow out of control and eventually form a mass (tumor) of cancerous (malignant) cells.

Factors that increase the risk of developing thyroid cancer include:

• Being female
• Being older
• Having a history of radiation treatments to the head and neck

Possible complications of Hurthle cell cancer include:

• Problems with swallowing and breathing. They can occur if the tumor grows and presses on the food tube (esophagus) and windpipe (trachea).
• Spread of the cancer. Hurthle cell cancer can spread (metastasize) to other tissues and organs, making treatment and recovery more difficult.