Diagnosis of Pituitary Tumor

Diagnosis of Pituitary Tumor

The following tests and procedures may be used to diagnose pituitary tumor:
  • Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
  • Eye exam: An exam to check vision and the general health of the eyes.
  • Visual field exam: An exam to check a person’s field of vision (the total area in which objects can be seen). This test measures both central vision (how much a person can see when looking straight ahead) and peripheral vision (how much a person can see in all other directions while staring straight ahead). The eyes are tested one at a time. The eye not being tested is covered.
  • Neurological exam: A series of questions and tests to check the brain, spinal cord, and nerve function. The exam checks a person’s mental status, coordination, and ability to walk normally, and how well the muscles, senses, and reflexes work. This may also be called a neuro exam or a neurologic exam.
  • MRI (magnetic resonance imaging) with gadolinium: A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the brain and spinal cord. A substance called gadolinium is injected into a vein. The gadolinium collects around the cancer cells so they show up brighter in the picture. This procedure is also called nuclear magnetic resonance imaging (NMRI).
  • CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the brain, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
  • Blood chemistry study: A procedure in which a blood sample is checked to measure the amounts of certain substances, such as hormones, released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it.
  • Blood tests: Tests to measure the levels of testosterone or estrogen in the blood. A higher or lower than normal amount of these hormones may be a sign of pituitary tumor.
  • Twenty-four-hour urine test: A test in which urine is collected for 24 hours to measure the amounts of certain substances. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that makes it. A higher than normal amount of the hormone cortisol may be a sign of a pituitary tumor.
  • High- dose dexamethasone suppression test: A test in which one or more high doses of dexamethasone are given. The level of cortisol is checked from a sample of blood or from urine that is collected for three days.
  • Low-dose dexamethasone suppression test: A test in which one or more small doses of dexamethasone are given. The level of cortisol is checked from a sample of blood or from urine that is collected for three days.
  • Venous sampling for pituitary tumors: A procedure in which a sample of blood is taken from veins coming from the pituitary gland. The sample is checked to measure the amount of ACTH released into the blood by the gland. Venous sampling may be done if blood tests show there is a tumor making ACTH, but the pituitary gland looks normal in the imaging tests.
  • Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.
  • Immunohistochemistry study: A laboratory test in which a substance such as an antibody, dye, or radioisotope is added to a sample of cancer tissue to test for certain antigens. This type of study is used to tell the difference between different types of cancer.
  • Light and electron microscopy: A laboratory test in which cells in a sample of tissue are viewed under regular and high-powered microscopes to look for certain changes in the cells.
Factors Affecting Prognosis and Treatment Options The prognosis (chance of recovery) depends on the type of tumor and whether the tumor has spread into other areas of the central nervous system (brain and spinal cord) or outside of the central nervous system to other parts of the body. Treatment options depend on the following:
  • The type and size of the tumor.
  • Whether the tumor is making hormones.
  • Whether the tumor is causing problems with vision or other symptoms.
  • Whether the tumor has spread into the brain around the pituitary gland or to other parts of the body.
  • Whether the tumor has just been diagnosed or has recurred (come back).
 

Stages of Pituitary Tumors

The extent or spread of cancer is usually described as stages. There is no standard staging system for pituitary tumors. Once a pituitary tumor is found, MRI and CT scan are done to find out if the tumor has spread into the brain or to other parts of the body. Pituitary tumors are described by their size and grade, whether or not they make extra hormones, and whether the tumor has spread to other parts of the body. The following sizes are used:
  • Microadenoma: The tumor is smaller than 1 centimeter.
  • Macroadenoma: The tumor is 1 centimeter or larger.
 

Recurrent Pituitary Tumors

A recurrent pituitary tumor is cancer that has recurred (come back) after it has been treated. The cancer may come back in the pituitary gland or in other parts of the body.