Thyroid cancers usually causes appearance of a firm nodule. Sometimes it may also cause enlargement of surrounding glands (lymph nodes). Medullary carcinoma (or cancer) may also cause fatigue and diarrhea. Other symptoms usually occur because of the pressure of the tumor on adjacent structures (especially common in Anaplastic carcinoma) which includes:

  • Hoarseness of voice
  • Persistent cough
  • Difficulty in breathing
  • Difficulty in swallowing