Causes and Diagnoses

Causes and Diagnoses of Endocrine Cancer

The exact cause of endocrine cancer is unknown. The following are common risk factors that may be contributing causes, including:

  • Age: Different age groups are more likely to develop different types of endocrine tumors. For example, Merkel cell cancer is most common in people older than 70, while thyroid cancer can occur at any age.
  • Gender: Men are also more likely to develop Merkel cell cancer than women. However, women are two to three times more likely to develop thyroid cancer than men.
  • Immune suppression: People with the human immunodeficiency virus (HIV), the virus that causes acquired immunodeficiency syndrome (AIDS), and people whose immune systems are suppressed because of organ transplantation have a higher risk of developing a neuroendocrine tumor.
  • Arsenic exposure: Exposure to arsenic, a poisonous metal, may increase the risk of Merkel cell cancer.
  • Sun exposure: Because Merkel cell cancer often occurs on the sun-exposed areas of the head and neck, many doctors think that sun exposure may be a risk factor for developing the cancer.
  • Diet low in iodine: Iodine is needed for normal thyroid functioning. In the United States, iodine is added to salt to help prevent thyroid problems.


Before any diagnostic tests, you will receive a thorough physical examination that may include:

  • Laboratory tests: We may collect and test samples of your blood, urine and stool to check for abnormal levels of hormones, glucose and other substances.
  • Neurological examination: One of our neurologists may examine your central nervous system including your reflexes, motor and sensory skills, balance and coordination, and mental status.

You may also receive diagnostic procedures that include:

  • Biopsy: We will remove a small amount of tissue for examination under a microscope.
  • Computed tomography (CT) scan: CT uses X-rays to produce detailed, three-dimensional images of organs and bones.
  • Magnetic resonance imaging (MRI): An MRI uses magnetic fields instead of X-rays to produce detailed images of the body. MRI can also be used to measure the tumor’s size.
  • Positron emission tomography (PET) scan: This uses small amounts of radioactive material to help measure body functions, such as blood flow and metabolism, in order to diagnose and determine the advancement of diseases.

Your care team will review your test results with you. If needed, our specialists will work with you and your primary care physician to develop a course of treatment that best suits your needs.