Medullary thyroid cancer is a rare form of thyroid cancer, accounting for only 3 to 4 percent of thyroid cancer diagnoses. Because of this, detecting the cancer early can be difficult.

Medullary thyroid cancer commonly advances from the thyroid into the lymph nodes. Undiagnosed medullary thyroid cancer can spread into other neck tissues and eventually reach the liver, lungs, bone, and brain. Once it reaches distant parts of the body it’s unlikely to be cured.

Early Detection

The earlier medullary thyroid cancer is found, the more likely it can be stopped and treated. Unfortunately, there may be no early warning signs of the cancer. The noticeable signs and symptoms like hoarseness, difficulty swallowing, or throat lumps often don’t appear until the tumor has advanced.

Common Symptoms

While not everyone will have the same symptoms, here are some of the most common signs of medullary thyroid cancer:

  • Neck lump: A single lump on the front of the neck is the most common symptom. It’s often discovered during a routine physical exam. But research has shown that once the lump is detected, the cancer has typically already spread to the neck lymph nodes.
    The American Cancer Society recommends that doctors examine the thyroid during routine physical exams. Some doctors recommend annual neck self-exams twice a year to feel for unusual growths.
    Lumps in the thyroid area and neck are usually benign. But if you notice unusual swelling in your neck, contact your doctor immediately.
  • Neck pain: Pain in the front of the neck may be related to the growth of a thyroid tumor. This pain can also extend to the ears.
  • Hoarseness: The nerve that controls your vocal cords runs alongside the trachea near the thyroid. If cancer has spread to that vocal cord, it can affect the quality of your voice.
  • Coughing: Thyroid cancer can sometimes cause a persistent cough. You should see your doctor if you have a cough that’s unrelated to a cold or one that doesn’t go away.
  • Trouble swallowing (dysphagia): If a thyroid tumor becomes large enough, it can press on the esophagus and make swallowing difficult.
  • Shortness of breath (dyspnea): Similar to trouble swallowing, if a thyroid tumor is large enough it can push against the windpipe and interfere with breathing.

Other Signs and Symptoms

Other, more rare or unusual signs of medullary thyroid cancer that you should be aware of include:

  • Severe diarrhea: This is a symptom sometimes found in people with advanced medullary thyroid cancer. The tumor produces high levels of a hormone-like chemical called calcitonin, a prostaglandin that may cause severe diarrhea.
  • Cushing syndrome: In rare cases, adrenal tumors can cause Cushing syndrome, a condition that arises when a tumor secretes hormones that the thyroid wouldn’t normal create.
    Cushing syndrome associated with medullary thyroid cancer is uncommon, and likely accounts for only 2 to 6 percent of Cushing syndrome cases. The syndrome is more commonly caused by the pituitary gland overproducing adrenocorticotropic hormone (ACTH) or by taking oral corticosteroid medication.
    People affected by Cushing syndrome can develop a moon face, fat deposits on the upper back and waist, weakness and purple skin striations, and high blood pressure, among other symptoms.
  • Facial flushing: A red face, neck, or chest paired with warm or burning sensations can be a sign of many conditions. Tumors or other abnormal growths can overproduce hormones, triggering flushing. The symptom can also be a response to certain drugs, foods, alcohol, or menopause.
  • Bone pain: People with medullary thyroid cancer may have bone pain if the cancer has spread to form bone lesions.
  • Lethargy: Many people with advanced cancer may feel physically, emotionally, or mentally tired. The causes of fatigue during cancer are complex and not well understood.
  • Weight loss: Unusual weight loss is a symptom of advanced medullary thyroid cancer that has spread beyond the thyroid into other organs.

If you experience any of these symptoms, especially if there’s a family history of medullary thyroid cancer, go see your doctor. Being attentive to your health is often one of the best ways to detect cancer early.